PC00000	1.00.00.00.00	protein class	
PC00197	1.01.00.00.00	receptor	A molecular structure within a cell or on the cell surface characterized by selective binding of a specific substance and a specific physiologic effect that accompanies the binding.
PC00021	1.01.01.00.00	G-protein coupled receptor	Cell surface receptors that are coupled to G proteins and have 7 transmembrane spanning domains.
PC00194	1.01.02.00.00	protein kinase receptor	A protein that has an extracellular ligand binding domain, a single transmembrane domain and an intracellular kinase domain.
PC00233	1.01.02.01.00	tyrosine protein kinase receptor	A protein that has an extracellular ligand binding domain, a single transmembrane domain and an intracellular tyrosine kinase domain that phosphorylates protein tyrosine residues.
PC00205	1.01.02.02.00	serine/threonine protein kinase receptor	A protein that has an extracellular ligand binding domain, a single transmembrane domain and an intracellular serine or threonine kinase domain that phosphorylates protein serine or threonine residues.
PC00084	1.01.03.00.00	cytokine receptor	A receptor that binds to cytokines and signals through particular signaling pathways, such as STAT pathway.  The chemokine GPCRs are excluded from this group, and can be found under G-protein coupled receptor.
PC00231	1.01.03.01.00	type I cytokine receptor	Type I cytokine receptors are transmembrane receptors expressed on the surface of cells that recognize and respond to cytokines with four _-helical strands. These receptors are also known under the name hemopoietin receptors, and share a common amino acid motif (WSXWS) in the extracellular portion adjacent to the cell membrane. Members of the type I cytokine receptor family includes type I interleukin receptors and colony stimulating receptors
PC00232	1.01.03.02.00	type II cytokine receptor	Type II cytokine receptors are transmembrane proteins that are expressed on the surface of certain cells, which bind and respond to a select group of cytokines. These receptors are similar to type I cytokine receptors except they do not possess the signature sequence WSXWS that is characteristic of type I receptors.  Typical examples are interferon alpha, beta, gamma receptors, and interleukin 10, 20, 22, and 28 receptors
PC00035	1.01.03.03.00	TGF-beta receptor	A transmembrane receptor protein whose ligand is member of TGF-beta family member.
PC00230	1.01.03.04.00	tumor necrosis factor receptor	A transmembrane receptor protein whose ligand is tumor necrosis factor.
PC00075	1.01.03.05.00	chemokine receptor	
PC00124	1.01.03.06.00	immunoglobulin receptor superfamily	A receptor that contains an immunoglobulin domain.  It is often involved in immune response.  Some of the common members in this category are T cell receptors and IgG receptors.
PC00141	1.01.05.00.00	ligand-gated ion channel	A transmembrane ion channel whose permeability is increased by the binding of a specific ligand.
PC00134	1.01.05.02.00	ionotropic glutamate receptor	A transmembrane ion channel whose permeability is increased by the binding of glutamate.
PC00001	1.01.05.02.01	AMPA receptor	The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (also known as AMPA receptor, AMPAR, or quisqualate receptor) is a non-NMDA-type ionotropic transmembrane receptor for glutamate that mediates fast synaptic transmission in the central nervous system (CNS).  Its name is derived from its ability to be activated by the artificial glutamate analog, AMPA. AMPARs are found in many parts of the brain and are the most commonly found receptor in the nervous system.
PC00136	1.01.05.02.02	kainate receptor	Kainate receptors, or KARs, are non-NMDA ionotropic receptors which respond to the neurotransmitter glutamate. They were first identified as a distinct receptor type through their selective activation by the agonist kainate, a drug first isolated from red alga Digenea simplex. Kainate receptors are involved in excitatory neurotransmission by activating postsynaptic receptors, and in inhibitory neurotransmission by modulating release of the inhibitory neurotransmitter GABA through a presynaptic mechanism.
PC00030	1.01.05.02.03	NMDA receptor	The NMDA (N-methyl D-aspartate) receptor (NMDAR) is an ionotropic receptor for glutamate (NMDA is a name of its selective specific agonist). Activation of NMDA receptors results in the opening of an ion channel that is nonselective to cations. This allows flow of Na+ and small amounts of Ca2+ ions into the cell and K+ out of the cell.
PC00037	1.01.05.01.00	acetylcholine receptor	A transmembrane ion channel whose permeability is increased by the binding of acetylcholine.
PC00164	1.01.05.01.01	nicotinic acetylcholine receptor	Nicotinic acetylcholine receptors, or nAChRs, are cholinergic receptors that can be activated by the binding of the neurotransmitter acetylcholine (ACh), and nicotin.  Nicotinic acetylcholine receptors are present in many tissues in the body, and are the best studied of the ionotropic receptors.[1] The neuronal receptors are found in the central nervous system and the peripheral nervous system. The neuromuscular receptors are found in the neuromuscular junctions of somatic muscles; stimulation of these receptors causes muscular contraction
PC00159	1.01.05.01.02	muscarinic acetylcholine receptor	Muscarinic receptors, or mAChRs, are G protein-coupled acetylcholine receptors found in the plasma membranes of certain neurons and other cells. They play several roles, including acting as the main end-receptor stimulated by acetylcholine released from postganglionic fibers in the parasympathetic nervous system.
PC00023	1.01.05.03.00	GABA receptor	A transmembrane ion channel whose permeability is increased by the binding of gamma aminobutyric acid.
PC00109	1.01.05.04.00	glycine receptor	The glycine receptor, which is the receptor for the amino acid neurotransmitter glycine, is one of the most widely distributed inhibitory receptors in the central nervous system and has important roles in a variety of physiological processes, especially in mediating inhibitory neurotransmission in the spinal cord and brain stem. 
PC00206	1.01.05.05.00	serotonin receptor	Serotonin receptors are receptors for the neurotransmitter and peripheral signal mediator serotonin, also known as 5-hydroxytryptamine or 5-HT (therefore, they are also called 5-HT receptors).  They are located on the cell membrane of nerve cells and other cell types including smooth muscle in animals, and mediate the effects of serotonin as the endogenous ligand and of a broad range of pharmaceutical and hallucinogenic drugs.  They affect the release and activity of other neurotransmitters such as glutamate, dopamine and GABA. 
PC00080	1.01.05.06.00	cyclic nucleotide-gated ion channel	A transmembrane ion channel whose permeability is increased by the binding of cyclic nucleotide, such as cAMP or cGMP.
PC00207	1.02.00.00.00	signaling molecule	A molecule that transduces a signal between cells.
PC00083	1.02.01.00.00	cytokine	A small protein or biological factor that is released by cells and have specific effects on cell-cell interaction, communication and behavior of other cells.  It contains interleukins, lymphokines, TNF-alpha and interferons.  Growth factors are generally not included here, although TGF-beta family members, CNTF and LIF are exceptions.
PC00128	1.02.01.01.00	interleukin superfamily	A cytokine produced by lymphocytes, monocytes and various other cell types and are released by cells in response to antigenic and non-antigenic stimuli. To date, there are 12 interleukins identified.  Their function is to modulate inflammation and immunity by regulating growth, mobility and differentiation of lymphoid and other cells.
PC00127	1.02.01.02.00	interferon superfamily	A family of glycoproteins that plays an important role in fighting viral infections by preventing viral multiplication in cells.
PC00036	1.02.01.03.00	TGF-beta superfamily member	A member that belongs to the superfamily related to transforming growth factor beta (TGF beta), a multifunctional peptide that controls proliferation, differentiation, and other functions in many cell types.  Members in this superfamily, in addition to TGF beta, bone morphogenetic proteins (BMPs), activin/inhibins, mullerian inhibiting substance, and glial cell line-derived neurotrophic factor (GDNF).
PC00229	1.02.01.04.00	tumor necrosis factor family member	A multifunctional proinflammatory cytokine, with effects on lipid metabolism, coagulation, insulin resistance, and endothelial function.
PC00074	1.02.01.05.00	chemokine	Proteins that are chemotactic for leucocytes.  They are regarded as cytokines by some people.
PC00005	1.02.01.05.01	CC chemokine	Also called beta-chemokines that have two adjacent cysteines near their amino terminus.  Examples are CCL1-28.
PC00008	1.02.01.05.02	CXC chemokine	Also called alpha-chemokines that have the two N-terminal cysteines separated by one amino acid, represented in this name with an X.  Examples are CXC1-17.
PC00004	1.02.01.05.03	C chemokine	Also known as gamma-chemokine that has only two cysteines; one N-terminal cysteine and one cysteine downstream.  Two chemokines have been described for this subgroup and are called XCL1 (lymphotactin-_) and XCL2 (lymphotactin-beta).
PC00007	1.02.01.05.04	CX3C chemokine	Also known as d-chemokine that have three amino acids between the two cysteines.  The only CX3C chemokine discovered to date is called fractalkine (or CX3CL1).
PC00112	1.02.03.00.00	growth factor	A complex family of biological factors that are produced by the body to control growth, division and maturation of various cell types.
PC00163	1.02.03.01.00	neurotrophic factor	A signaling molecule involved in the nutrition (or maintenance) of neural tissue.  The classic example is the nerve growth factor.
PC00179	1.02.04.00.00	peptide hormone	A protein or peptide that acts as a hormone.
PC00162	1.02.04.01.00	neuropeptide	A peptide with direct synaptic effects (peptide neurotransmitters) or indirect modulatory effects on the nervous system (peptide neuromodulators).
PC00152	1.02.07.00.00	membrane-bound signaling molecule	A signaling molecule that is membrane-bound and not secreted.
PC00137	1.03.00.00.00	kinase	An enzyme that catalyzes the transfer of a phosphate from ATP to a second substrate.
PC00193	1.03.01.00.00	protein kinase	An enzyme that catalyzes the transfer of a phosphate from ATP to the hydroxyl side chains on proteins, causing changes in function.
PC00233	1.03.01.01.00	tyrosine protein kinase receptor	A protein that has an extracellular ligand binding domain, a single transmembrane domain and an intracellular tyrosine kinase domain that phosphorylates protein tyrosine residues.
PC00168	1.03.01.02.00	non-receptor tyrosine protein kinase	A soluble protein catalyzing transfer of phosphate from ATP to tyrosine residue.
PC00205	1.03.01.03.00	serine/threonine protein kinase receptor	A protein that has an extracellular ligand binding domain, a single transmembrane domain and an intracellular serine or threonine kinase domain that phosphorylates protein serine or threonine residues.
PC00167	1.03.01.04.00	non-receptor serine/threonine protein kinase	A soluble protein catalyzing transfer of phosphate from ATP to serine or threonine residue.
PC00065	1.03.02.00.00	carbohydrate kinase	An enzyme that catalyzes the phosphorylation of a sugar or carbohydrate.
PC00172	1.03.03.00.00	nucleotide kinase	An enzyme that catalyzes the phosphorylation of a nucleotide.
PC00045	1.03.04.00.00	amino acid kinase	An enzyme that catalyzes the phosphorylation of an amino acid.
PC00181	1.04.00.00.00	phosphatase	An enzyme that hydrolyzes phosphomonoesters.
PC00195	1.04.01.00.00	protein phosphatase	An enzyme that hydrolyzes phosphomonoesters in proteins.
PC00066	1.04.02.00.00	carbohydrate phosphatase	An enzyme that hydrolyzes phosphomonoesters in carbohydrate.
PC00173	1.04.03.00.00	nucleotide phosphatase	An enzyme that hydrolyzes phosphomonoesters in nucleotides.
PC00190	1.05.00.00.00	protease	Enzymes that hydrolyze peptide bonds.
PC00153	1.05.01.00.00	metalloprotease	A protease whose catalytic activity requires a transition metal.
PC00081	1.05.02.00.00	cysteine protease	Peptide hydrolases that have a cysteine involved in the catalytic process. This group of enzymes is inactivated by sulfhydryl reagents.
PC00203	1.05.03.00.00	serine protease	One of a group of endoproteases from both animal and bacterial sources that share a common reaction mechanism based on formation of an acyl enzyme intermediate on a specific active serine residue.
PC00053	1.05.05.00.00	aspartic protease	Peptide hydrolases that have two aspartyl residues in the catelytic process.
PC00095	1.06.00.00.00	enzyme modulator	A protein that modulates the activity of a select group of an enzyme such as kinases, phosphatases, protease, and G-proteins.
PC00140	1.06.01.00.00	kinase modulator	A protein that directly interacts with a kinase and affects its activity.
PC00138	1.06.01.01.00	kinase activator	A protein that directly interacts with a kinase and activates or enhance its activity.
PC00139	1.06.01.02.00	kinase inhibitor	A protein that directly interacts with a kinase and inhibits its activity.
PC00184	1.06.02.00.00	phosphatase modulator	A protein that directly interacts with a phosphatase and affects its activity.
PC00182	1.06.02.01.00	phosphatase activator	A protein that directly interacts with a phosphatase and activates or enhance its activity.
PC00183	1.06.02.02.00	phosphatase inhibitor	A protein that directly interacts with a phosphatase and inhibits its activity.
PC00020	1.06.03.00.00	G-protein	A GTP-binding protein that is either part of the heterotrimeric G protein class or of the small GTP-binding class.
PC00117	1.06.03.01.00	heterotrimeric G-protein	the heterotrimeric G proteins that associate with receptors of the seven transmembrane domain superfamily and are involved in signal transduction.
PC00208	1.06.03.02.00	small GTPase	The small G proteins are a diverse group of monomeric GTPases that include ras, rab, rac and rho and that play an important part in regulating many intracellular processes including cytoskeletal organization and secretion.
PC00022	1.06.04.00.00	G-protein modulator	A protein that directly interacts with a G-protein and affects its activity.
PC00113	1.06.04.01.00	guanyl-nucleotide exchange factor	An enzyme that catalyzes the exchange of GDP and GTP in a G-protein.
PC00191	1.06.05.00.00	protease inhibitor	Compounds which inhibit or antagonize the biosynthesis or actions of proteases.
PC00154	1.06.05.01.00	metalloprotease inhibitor	Compounds that inhibit or antagonize the biosynthesis or actions of metalloproteases, proteases whose catalytic activity requires a transition metal.
PC00082	1.06.05.02.00	cysteine protease inhibitor	Compounds that inhibit or antagonize the biosynthesis or actions of cysteine-type proteases, peptide hydrolases that have a cysteine involved in the catalytic process.
PC00204	1.06.05.03.00	serine protease inhibitor	Compounds that inhibit or antagonize the biosynthesis or actions of serine-type proteases, one of a group of endoproteases from both animal and bacterial sources that share a common reaction mechanism based on formation of an acyl enzyme intermediate on a specific active serine residue.
PC00054	1.06.05.05.00	aspartic protease inhibitor	Compounds that inhibit or antagonize the biosynthesis or actions of aspartic-type proteases.
PC00060	1.07.00.00.00	calcium-binding protein	A protein that participates in calcium cell signalling pathways by binding to Ca2+.
PC00131	1.07.01.00.00	intracellular calcium-sensing protein	Intracellular signaling peptides and proteins that bind to Ca2+. They undergo allosteric changes when bound to Ca2+ that affects their interaction with other signal-transducing molecules. They differ from calcium sensing receptors which sense extracellular calcium levels.
PC00061	1.07.01.01.00	calmodulin	A calcium binding protein that are similar to calmodulin and are called EF hand proteins.
PC00062	1.07.01.02.00	calnexin	Calnexin (CNX) is a 90kDa integral protein of the endoplasmic reticulum (ER).  It is involved in protein folding.  ATP and Ca++ are two of the cofactors involved in its binding to the substrate.
PC00063	1.07.01.03.00	calreticulin	Calreticulin is a multifunctional protein that binds Ca2+ ions, rendering it inactive. The Ca2+ is bound with low affinity, but high capacity, and can be released on a signal.  In addition, it is also involved in protein folding of newly synthesized peptide.
PC00106	1.07.01.04.00	gelosin	A protein produced by macrophages that severs actin filaments and forms a cap on the newly exposed filament end. Gelsolin is activated by calcium ions and participates in the assembly and disassembly of actin, thereby increasing the motility of some cells.
PC00050	1.07.02.00.00	annexin	Group of calcium-binding proteins that interact with acidic membrane phospholipids in membranes. They contain 4 or 8 repeats of a 61 amino acid domain that folds into 5 a helices.
PC00238	1.07.03.00.00	vitamin D-dependent calcium binding protein	A protein that plays a fundamental role in the Vitamin D mediated transport of calcium. It is found in the intestine, kidneys, egg shell gland, brain, and possibly other organs.
PC00064	1.07.04.00.00	calsequestrin	An acidic protein found in sarcoplasmic reticulum that binds calcium. It plays the role of sequestering calcium transported to the interior of the intracellular vesicle.
PC00218	1.08.00.00.00	transcription factor	A protein required for the regulation of RNA polymerase by specific regulatory sequences in or near a gene.
PC00244	1.08.01.00.00	zinc finger transcription factor	A transcription factor containing zinc finger domain(s), which is composed of conserved cysteines and histidines co-ordinate with zinc ion(s).  Examples of zinc finger domains are C2H2 zinc finger, C3HC4 zinc finger, CHC2 zinc finger, etc.
PC00169	1.08.01.01.00	C4 zinc finger nuclear receptor	A receptor of steroid hormones that traverses the nuclear membrane to activate transcription.
PC00248	1.08.01.02.00	C2H2 zinc finger transcription factor	A zinc-coordinating transcription factor with C2H2 zinc finger DNA binding domains.
PC00029	1.08.01.02.01	KRAB box transcription factor	A transcription factor containing a C2H2 zinc finger domain and a KRAB (Kruppel-associated box) domain.
PC00249	1.08.01.03.00	C6 zinc finger transcription factor	A zinc-coordinating transcription factor with a C6 zinc finger DNA binding domain.
PC00024	1.08.02.00.00	HMG box transcription factor	A transcription factor containing high mobility group protein (HMG) box.
PC00055	1.08.03.00.00	basic helix-loop-helix transcription factor	A transcription factor containing helix-loop-helix (HLH) DNA binding domain.
PC00056	1.08.04.00.00	basic leucine zipper transcription factor	A transcription factor that contains the basic leucine zipper (bZIP) domain, where one part of the domain contains a region that mediates sequence specific DNA binding properties and the leucine zipper that is required for the dimerization of two DNA binding regions.
PC00006	1.08.04.01.00	CREB-related transcription factor	A transcription factor that regulates transcription by binding to the cyclic AMP response element (CRE).
PC00116	1.08.05.00.00	helix-turn-helix transcription factor	A transcription factor that has the helix-turn-helix (HTH) domain, a major DNA-binding structural motif composed of two _ helices joined by a short strand of amino acids.
PC00119	1.08.05.01.00	homeodomain transcription factor	A transcription factor containing the homeobox domain. It is usually involved in the control of gene expression during morphogenesis and development.
PC00178	1.08.05.02.00	paired box transcription factor	A tissue specific transcription factor that contains a paired domain and usually a partial or complete homeodomain.
PC00245	1.08.05.03.00	Lambda repressor-like transcription factor	A helix-turn-helix transcription factor with a similar DNA binding domain fold to the Lambda repressor in bacteria.
PC00246	1.08.05.04.00	winged helix/forkhead transcription factor	A helix-turn-helix transcription factor with a forkhead DNA binding domain.
PC00247	1.08.05.05.00	Trp repressor-like transcription factor	A helix-turn-helix transcription factor with a similar DNA binding domain fold to the Trp repressor in bacteria.
PC00217	1.08.08.00.00	transcription cofactor	A protein that has no DNA binding domains, but regulates transcription by binding to other transcription factors.
PC00250	1.08.09.00.00	MADS box transcription factor	A transcription factor with a MADS box DNA binding domain.
PC00251	1.08.10.00.00	immunoglobulin fold transcription factor	A transcription factor with a DNA binding domain with a fold similar to immunoglobulins.
PC00252	1.08.10.01.00	Rel homology transcription factor	An immunoglobulin fold transcription factor with a Rel homology region (RHR) DNA binding domain.
PC00253	1.08.10.02.00	P53-like transcription factor	An immunoglobulin fold transcription factor with a DNA binding domain with a fold similar to p53.
PC00254	1.08.10.03.00	Runt transcription factor	An immunoglobulin fold transcription factor with a Runt domain.
PC00255	1.08.11.00.00	TATA-binding transcription factor	A transcription factor that binds specifically to the minor groove of the TATA-box motif.
PC00256	1.08.12.00.00	SMAD-like transcription factor	A transcription factor with a similar DNA binding domain alpha/beta fold to the SMAD (related to Drosophila “mothers against decapentaplegic” gene product) proteins.
PC00171	1.09.00.00.00	nucleic acid binding	A molecule that binds a nucleic acid.  It can be an enzyme or a binding protein.
PC00009	1.09.01.00.00	DNA binding protein	A protein that has DNA binding domains and binds DNA.  Transcription factors are DNA binding proteins, but they are not included in this category.
PC00018	1.09.01.01.00	DNA-directed DNA polymerase	An enzyme involved in template directed synthesis of DNA from deoxyribonucleotide triphosphates.
PC00015	1.09.01.02.00	DNA polymerase processivity factor	A protein that enhances the processivity of DNA polymerase.
PC00199	1.09.01.03.00	replication origin binding protein	A protein that binds specifically to the origin of replication.
PC00014	1.09.01.04.00	DNA photolyase	A DNA repair enzyme that recognizes and monomerizes pyrimidine dimers using visible light.
PC00012	1.09.01.05.00	DNA ligase	An enzyme that seals nicks in one strand of double stranded DNA, by forming a phosphodiester linkage between a free 3 prime OH and 5 prime phosphate groups of two adjacent nucleotide residues.
PC00010	1.09.01.06.00	DNA glycosylase	An enzyme that recognizes altered bases in DNA and catalyzes their removal by cleaving the glycosidic bond between the base and the deoxyribose sugar.
PC00013	1.09.01.07.00	DNA methyltransferase	An enzyme that methylates specific bases in DNA.
PC00017	1.09.01.08.00	DNA topoisomerase	Enzymes that change the degree of supercoiling in DNA by cutting one or both strands.
PC00071	1.09.01.10.00	centromere DNA-binding protein	A protein that binds specifically to centromeric DNA.
PC00086	1.09.01.11.00	damaged DNA-binding protein	A protein that binds specifically to damaged DNA.
PC00016	1.09.01.12.00	DNA strand-pairing protein	An enzyme that pairs complementary DNA molecules during genetic recombination.
PC00118	1.09.01.13.00	histone	A protein found in the nuclei of all eukaryotic cells where it is complexed to DNA to form chromatin.
PC00077	1.09.01.14.00	chromatin/chromatin-binding protein	A non-histone protein that either binds DNA to comprise chromatin or which binds chromatin.
PC00098	1.09.01.15.00	exodeoxyribonuclease	An enzyme that cleaves DNA sequentially from the free ends of a linear nucleic acid substrate.
PC00093	1.09.01.16.00	endodeoxyribonuclease	One of a large group of enzymes that cleaves DNA at an internal position in the chain.
PC00011	1.09.01.17.00	DNA helicase	An enzyme that promotes the unwinding of duplex DNA.
PC00031	1.09.02.00.00	RNA binding protein	A protein that binds RNA and is involved in RNA processing or metabolism.
PC00200	1.09.02.01.00	reverse transcriptase	A DNA polymerase that uses RNA as a template.
PC00019	1.09.02.02.00	DNA-directed RNA polymerase	An enzyme that polymerizes ribonucleotides using a DNA template.  Factors involved in this process are categorized under TRANSCRIPTION FACTOR.
PC00189	1.09.02.03.00	primase	The enzyme that polymerizes ribonucleoside triphosphates to form oligoribonucleotides in a 5 prime to 3 prime direction.
PC00033	1.09.02.04.00	RNA methyltransferase	An enzyme that methylates specific bases in RNA.
PC00147	1.09.02.05.00	mRNA processing factor	A factor involved in mRNA processing, including capping, polyadenylation and splicing.
PC00145	1.09.02.05.01	mRNA capping factor	A factor involved in mRNA capping.
PC00146	1.09.02.05.02	mRNA polyadenylation factor	A factor involved in mRNA polyadenylation.
PC00148	1.09.02.05.03	mRNA splicing factor	A factor involved in mRNA splicing.
PC00201	1.09.02.06.00	ribonucleoprotein	Heterogeneous nuclear RNA, small nuclear ribonucleoproteins, and signal recognition particles.
PC00223	1.09.02.07.00	translation factor	A non-ribosomal protein involved in translation initiation, elongation or termination.
PC00224	1.09.02.07.01	translation initiation factor	A non-ribosomal protein involved in translation initiation.
PC00222	1.09.02.07.02	translation elongation factor	A non-ribosomal protein involved in translation elongation.
PC00225	1.09.02.07.03	translation release factor	A non-ribosomal protein involved in translation release.
PC00202	1.09.02.08.00	ribosomal protein	A protein that comprises part of the ribosome.
PC00099	1.09.02.09.00	exoribonuclease	An enzyme that cleaves RNA sequentially from the free ends of a linear nucleic acid substrate.
PC00094	1.09.02.10.00	endoribonuclease	One of a large group of enzymes that cleaves RNA at an internal position in the chain.
PC00032	1.09.02.11.00	RNA helicase	An enzyme that promotes the unwinding of RNA.
PC00170	1.09.03.00.00	nuclease	An enzyme that cleaves the phosphodiester bonds of a nucleic acid.
PC00098	1.09.03.01.00	exodeoxyribonuclease	An enzyme that cleaves DNA sequentially from the free ends of a linear nucleic acid substrate.
PC00093	1.09.03.02.00	endodeoxyribonuclease	One of a large group of enzymes that cleaves DNA at an internal position in the chain.
PC00099	1.09.03.04.00	exoribonuclease	An enzyme that cleaves RNA sequentially from the free ends of a linear nucleic acid substrate.
PC00094	1.09.03.05.00	endoribonuclease	One of a large group of enzymes that cleaves RNA at an internal position in the chain.
PC00115	1.09.04.00.00	helicase	An enzyme that promotes the unwinding of duplex nucleic acids.
PC00032	1.09.04.01.00	RNA helicase	An enzyme that promotes the unwinding of RNA.
PC00011	1.09.04.02.00	DNA helicase	An enzyme that promotes the unwinding of duplex DNA.
PC00227	1.10.00.00.00	transporter	A class of transmembrane proteins that allows substances to cross plasma membranes far faster than would be possible by diffusion alone.   Please note that ion channel has its own category and is not included here.
PC00133	1.10.01.00.00	ion channel	A protein creating a highly selective transmembrane pore that presents a hydrophilic channel for specific ions to cross a lipid bilayer.
PC00058	1.10.01.01.00	calcium channel	A transmembrane ion channel that displays selective permeability to calcium ions.
PC00240	1.10.01.01.01	voltage-gated calcium channel	A transmembrane ion channel whose selective permeability to calcium is sensitive to the transmembrane potential difference.
PC00209	1.10.01.02.00	sodium channel	A transmembrane ion channel that displays selective permeability to sodium ions.
PC00243	1.10.01.02.01	voltage-gated sodium channel	A transmembrane ion channel whose selective permeability to sodium is sensitive to the transmembrane potential difference.
PC00188	1.10.01.03.00	potassium channel	A transmembrane ion channel that displays selective permeability to potassium ions.
PC00242	1.10.01.03.01	voltage-gated potassium channel	A transmembrane ion channel whose selective permeability to potassium is sensitive to the transmembrane potential difference.
PC00059	1.10.01.03.02	calcium-activated potassium channel	A potassium channel whose permeability to potassium is activated by intracellular Ca2+ concentration.
PC00132	1.10.01.03.03	inward rectifier potassium channel	A potassium channel that allows potassium ion flow through the channel more easily in the inward direction.
PC00213	1.10.01.03.04	tandem pore domain potassium channel	The name is derived from the fact that the _ subunits consist of four transmembrane segments, each containing two pore loops. As such, they structurally correspond to two inward-rectifier _ subunits and thus form dimers in the membrane.  Members in this family are also known as leak channels.
PC00049	1.10.01.04.00	anion channel	A transmembrane ion channel that is selectively permeable to anions.
PC00076	1.10.01.04.01	chloride channel	A transmembrane ion channel that conducts Cl- as well as other anions such as HCO3-, I-, SCN-, and NO3-. Chloride channels are important for setting cell resting membrane potential and maintaining proper cell volume. 
PC00239	1.10.01.04.02	voltage-gated anion channel	Voltage-dependent anion channels are a class of porin ion channel, and are located on the outer mitochondrial membrane.
PC00141	1.10.01.05.00	ligand-gated ion channel	A transmembrane ion channel whose permeability is increased by the binding of a specific ligand.
PC00134	1.10.01.05.01.00	ionotropic glutamate receptor	A transmembrane ion channel whose permeability is increased by the binding of glutamate.
PC00001	1.10.01.05.01.01	AMPA receptor	The alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (also known as AMPA receptor, AMPAR, or quisqualate receptor) is a non-NMDA-type ionotropic transmembrane receptor for glutamate that mediates fast synaptic transmission in the central nervous system (CNS).  Its name is derived from its ability to be activated by the artificial glutamate analog, AMPA. AMPARs are found in many parts of the brain and are the most commonly found receptor in the nervous system.
PC00136	1.10.01.05.01.02	kainate receptor	Kainate receptors, or KARs, are non-NMDA ionotropic receptors which respond to the neurotransmitter glutamate. They were first identified as a distinct receptor type through their selective activation by the agonist kainate, a drug first isolated from red alga Digenea simplex. Kainate receptors are involved in excitatory neurotransmission by activating postsynaptic receptors, and in inhibitory neurotransmission by modulating release of the inhibitory neurotransmitter GABA through a presynaptic mechanism.
PC00030	1.10.01.05.01.03	NMDA receptor	The NMDA (N-methyl D-aspartate) receptor (NMDAR) is an ionotropic receptor for glutamate (NMDA is a name of its selective specific agonist). Activation of NMDA receptors results in the opening of an ion channel that is nonselective to cations. This allows flow of Na+ and small amounts of Ca2+ ions into the cell and K+ out of the cell.
PC00037	1.10.01.05.02.00	acetylcholine receptor	A transmembrane ion channel whose permeability is increased by the binding of acetylcholine.
PC00164	1.10.01.05.02.01	nicotinic acetylcholine receptor	Nicotinic acetylcholine receptors, or nAChRs, are cholinergic receptors that can be activated by the binding of the neurotransmitter acetylcholine (ACh), and nicotin.  Nicotinic acetylcholine receptors are present in many tissues in the body, and are the best studied of the ionotropic receptors.[1] The neuronal receptors are found in the central nervous system and the peripheral nervous system. The neuromuscular receptors are found in the neuromuscular junctions of somatic muscles; stimulation of these receptors causes muscular contraction
PC00159	1.10.01.05.02.02	muscarinic acetylcholine receptor	Muscarinic receptors, or mAChRs, are G protein-coupled acetylcholine receptors found in the plasma membranes of certain neurons and other cells. They play several roles, including acting as the main end-receptor stimulated by acetylcholine released from postganglionic fibers in the parasympathetic nervous system.
PC00023	1.10.01.05.03	GABA receptor	A transmembrane ion channel whose permeability is increased by the binding of gamma aminobutyric acid.
PC00109	1.10.01.05.04	glycine receptor	The glycine receptor, which is the receptor for the amino acid neurotransmitter glycine, is one of the most widely distributed inhibitory receptors in the central nervous system and has important roles in a variety of physiological processes, especially in mediating inhibitory neurotransmission in the spinal cord and brain stem. 
PC00206	1.10.01.05.05	serotonin receptor	Serotonin receptors are receptors for the neurotransmitter and peripheral signal mediator serotonin, also known as 5-hydroxytryptamine or 5-HT (therefore, they are also called 5-HT receptors).  They are located on the cell membrane of nerve cells and other cell types including smooth muscle in animals, and mediate the effects of serotonin as the endogenous ligand and of a broad range of pharmaceutical and hallucinogenic drugs.  They affect the release and activity of other neurotransmitters such as glutamate, dopamine and GABA. 
PC00080	1.10.01.05.06	cyclic nucleotide-gated ion channel	A transmembrane ion channel whose permeability is increased by the binding of cyclic nucleotide, such as cAMP or cGMP.
PC00241	1.10.01.06.00	voltage-gated ion channel	A transmembrane ion channel whose permeability to ions is sensitive to the transmembrane potential difference.
PC00240	1.10.01.06.01	voltage-gated calcium channel	A transmembrane ion channel whose selective permeability to calcium is sensitive to the transmembrane potential difference.
PC00243	1.10.01.06.02	voltage-gated sodium channel	A transmembrane ion channel whose selective permeability to sodium is sensitive to the transmembrane potential difference.
PC00242	1.10.01.06.03	voltage-gated potassium channel	A transmembrane ion channel whose selective permeability to potassium is sensitive to the transmembrane potential difference.
PC00239	1.10.01.06.04	voltage-gated anion channel	
PC00068	1.10.02.00.00	cation transporter	A major class of transport proteins that expend energy through ATP hydrolysis to move cation across the plasma membrane.
PC00002	1.10.02.01.00	ATP synthase	An integral membrane proteins that transport protons across a membrane against a concentration gradient. This transport is driven by hydrolysis of ATP by hydrogen-transporting ATP synthase.
PC00003	1.10.03.00.00	ATP-binding cassette (ABC) transporter	A superfamily of oligopeptide permease proteins responsible for transporting a wide range of substrates across membranes.
PC00067	1.10.04.00.00	carbohydrate transporter	A class of transport proteins that transport carbohydrate across the plasma membrane.
PC00046	1.10.05.00.00	amino acid transporter	A class of transport proteins that transport amino acid across the plasma membrane.
PC00158	1.10.06.00.00	mitochondrial carrier protein	A protein that is located in the inner membrane of mitochondria and transports small molecules or protons within the membrane bilayer.
PC00219	1.11.00.00.00	transfer/carrier protein	Proteins that carry specific substances in the blood or in the cell. They usually are not involved in transmembrane transport.
PC00052	1.11.01.00.00	apolipoprotein	The protein component of serum lipoproteins.
PC00107	1.11.02.00.00	globin	The polypeptide moiety of hemaglobin.  Both hemaglobin and myoblogin belong to this category.
PC00069	1.12.00.00.00	cell adhesion molecule	A protein that mediates cell-to-cell adhesion.
PC00125	1.12.01.00.00	immunoglobulin superfamily cell adhesion molecule	Immunoglobulin superfamily CAMs (IgSF CAMs) are either homophilic or heterophilic and bind integrins or different IgSF CAMs.  Examples are NCAMs, ICAMs, and PECAM.
PC00057	1.12.02.00.00	cadherin	An integral membrane protein involved in calcium dependent cell adhesion.
PC00126	1.12.03.00.00	integrin	The integrins are a family of heterophilic CAMs that bind IgSF CAMs or the extracellular matrix. They are heterodimers, consisting in two noncovalently-linked subunits, called alpha and beta
PC00085	1.13.00.00.00	cytoskeletal protein	Major constituent of the cytoskeleton found in the cytoplasm of eukaryotic cells. They form a flexible framework for the cell, provide attachment points for organelles and formed bodies, and make communication between parts of the cell possible.
PC00041	1.13.01.00.00	actin family cytoskeletal protein	A protein that is either actin itself or binds to actin to form the cytoskeleton of the cell.
PC00039	1.13.01.01.00	actin and actin related protein	An actin protein or a protein that is related to actin.
PC00165	1.13.01.02.00	non-motor actin binding protein	An actin binding protein that is not involved in motor function.
PC00040	1.13.01.03.00	actin binding motor protein	A family of motor ATPases that interact with F actin filaments.  A typical member in this category is myosin.
PC00157	1.13.02.00.00	microtubule family cytoskeletal protein	A protein that is either microtubule itself or binds to microtubule to form the cytoskeleton of the cell.
PC00228	1.13.02.01.00	tubulin	An abundant cytoplasmic protein in the microtubule family that is involved in nucleation of microtubule assembly during the cell cycle.
PC00166	1.13.02.02.00	non-motor microtubule binding protein	A nonmotor protein that binds to microtubule cytoskeletal protein.
PC00156	1.13.02.03.00	microtubule binding motor protein	A family of motor proteins that are responsible for moving vesicles and particles along the microtubule.  Typical examples are dynein and kinesin.
PC00129	1.13.03.00.00	intermediate filament	A cytoplasmic filament protein so named originally because their diameter (nominally 10 nm) in muscle cells was intermediate between thick and thin filaments.
PC00130	1.13.03.01.00	intermediate filament binding protein	A protein that binds to intermediate filament.
PC00102	1.14.00.00.00	extracellular matrix protein	A protein that is produced and secreted by cells and forms an intricate extracellular meshwork in which cells are embedded to construct tissues.
PC00103	1.14.01.00.00	extracellular matrix structural protein	A protein that forms the structural backbone of  extracellular matrix in which cells are embedded to construct tissues.
PC00100	1.14.02.00.00	extracellular matrix glycoprotein	An extracellular matrix protein which is conjugated with one or more covalently linked carbohydrate residues.
PC00101	1.14.03.00.00	extracellular matrix linker protein	An extracellular matrix protein which has multiple domains that confer the ability to interact with many extracellular substances.
PC00070	1.16.00.00.00	cell junction protein	Proteins that form specialized junctions between cells.
PC00105	1.16.01.00.00	gap junction	A protein that creates a gap junction.  A gap junction is a junction between two cells consisting of many pores that allow the passage of molecules.
PC00214	1.16.02.00.00	tight junction	A tight junction is a specialized intercellular junction in which the two plasma membranes are separated by only 1-2nm.  It is found near the apical surface of cells in simple epithelia, and forms a sealing gasket around the cell.
PC00176	1.19.00.00.00	oxidoreductase	An enzyme that catalyzes a redox reaction.
PC00177	1.19.01.00.00	oxygenase	An enzyme that catalyzes the incorporation of molecular oxygen into organic substrates.
PC00180	1.19.04.00.00	peroxidase	A heme enzyme that catalyzes reduction of hydrogen peroxide by a substrate that loses two hydrogen atoms.
PC00092	1.19.05.00.00	dehydrogenase	An enzyme that oxidizes a substrate by transferring hydrogen to an acceptor that is either NAD/NADP or a flavin enzyme.
PC00198	1.19.06.00.00	reductase	An enzyme that introduces an electron into its substrate from an electron donor.  The reaction is usually coupled with an oxidation reaction.
PC00175	1.19.07.00.00	oxidase	An enzyme that removes an electron from its substrate to an electron acceptor.  The reaction is usually coupled with a reduction reaction.
PC00122	1.19.09.00.00	hydroxylase	A type of enzyme that adds -OH groups to its substrate during hydroxylation by attaching oxygen atoms to it.
PC00220	1.20.00.00.00	transferase	Enzymes transferring a group from one compound (donor) to another compound (acceptor).  Kinase is a separate category, so it is not included here.
PC00137	1.20.01.00.00	kinase	An enzyme that catalyzes the transfer of a phosphate from ATP to a second substrate (EC2.7).
PC00193	1.20.01.01.00	protein kinase	An enzyme that catalyzes the transfer of a phosphate from ATP to the hydroxyl side chains on proteins, causing changes in function.
PC00233	1.20.01.01.01	tyrosine protein kinase receptor	A protein that has an extracellular ligand binding domain, a single transmembrane domain and an intracellular tyrosine kinase domain that phosphorylates protein tyrosine residues.
PC00168	1.20.01.01.02	non-receptor tyrosine protein kinase	A soluble protein catalyzing transfer of phosphate from ATP to tyrosine residue.
PC00205	1.20.01.01.03	serine/threonine protein kinase receptor	A protein that has an extracellular ligand binding domain, a single transmembrane domain and an intracellular serine or threonine kinase domain that phosphorylates protein serine or threonine residues.
PC00167	1.20.01.01.04	non-receptor serine/threonine protein kinase	A soluble protein catalyzing transfer of phosphate from ATP to serine or threonine residue.
PC00065	1.20.01.02.00	carbohydrate kinase	An enzyme that catalyzes the phosphorylation of a sugar or carbohydrate.
PC00172	1.20.01.03.00	nucleotide kinase	An enzyme that catalyzes the phosphorylation of a nucleotide.
PC00045	1.20.01.04.00	amino acid kinase	An enzyme that catalyzes the phosphorylation of an amino acid.
PC00174	1.20.02.00.00	nucleotidyltransferase	A class of enzymes that transfers nucleotidyl residues.
PC00155	1.20.03.00.00	methyltransferase	A class of enzymes that transfers methyl groups (EC2.1).
PC00013	1.20.03.01.00	DNA methyltransferase	An enzyme that methylates specific bases in DNA.
PC00033	1.20.03.02.00	RNA methyltransferase	An enzyme that methylates specific bases in RNA.
PC00221	1.20.06.00.00	transketolase	Together with transaldolase, links the pentose phosphate pathway with glycolysis by converting pentoses to hexoses.
PC00215	1.20.07.00.00	transaldolase	Together with transketolase, links the pentose phosphate pathway with glycolysis by converting pentoses to hexoses.
PC00038	1.20.08.00.00	acetyltransferase	An enzyme that catalyzes the transfer of an acetyl group, usually from acetyl coenzyme A, to another compound.
PC00111	1.20.09.00.00	glycosyltransferase	An enzyme that catalyzes the transfer of a sugar (monosaccharide) unit from a sugar nucleotide derivative to a sugar or amino acid acceptor (EC2.4).
PC00216	1.20.10.00.00	transaminase	A subclass of enzymes that catalyze the transfer of an amino group from a donor (generally an amino acid) to an acceptor (generally 2 keto acid) in a cyclic process using pyridoxal phosphate as a cofactor (EC2.6).
PC00042	1.20.11.00.00	acyltransferase	An enzyme of the transferase class that catalyzes the transfer of an acyl group from a donor (often the corresponding acyl coenzyme A derivative) to an acceptor compound (EC2.3).
PC00187	1.20.13.00.00	phosphorylase	An enzyme that hydrolyzes a substrate to yield a monosaccharide-phosphate product.
PC00121	1.21.00.00.00	hydrolase	Enzymes catalyzing hydrolysis of a variety of bonds, such as esters, glycosides, or peptides.  Protease and phosphatases are separate categories, so they are not included here.
PC00143	1.21.01.00.00	lipase	Enzymes that catalyze the hydrolysis of fats (monoglycerides, diglycerides and triglycerides) to glycerol and fatty acids. Calcium ions are usually required.
PC00186	1.21.01.01.00	phospholipase	Enzymes that hydrolyze ester bonds in phospholipids. They comprise two types: aliphatic esterases (phospholipase A1, A2 and B) that release fatty acids, and phosphodiesterases (types C and D) that release diacyl glycerol or phosphatidic acid respectively.
PC00097	1.21.02.00.00	esterase	Enzymes that catalyze the hydrolysis of organic esters to release an alcohol or thiol and acid.
PC00185	1.21.03.00.00	phosphodiesterase	Enzymes that cleave phosphodiesters to give a phosphomonoester and a free hydroxyl group.
PC00181	1.21.04.00.00	phosphatase	An enzyme that hydrolyzes phosphomonoesters.
PC00195	1.21.04.01.00	protein phosphatase	An enzyme that hydrolyzes phosphomonoesters in proteins.
PC00066	1.21.04.02.00	carbohydrate phosphatase	An enzyme that hydrolyzes phosphomonoesters in carbohydrate.
PC00173	1.21.04.03.00	nucleotide phosphatase	An enzyme that hydrolyzes phosphomonoesters in nucleotides.
PC00190	1.21.05.00.00	protease	Enzymes that hydrolyze peptide bonds.
PC00153	1.21.05.01.00	metalloprotease	A protease whose catalytic activity requires a transition metal.
PC00081	1.21.05.02.00	cysteine protease	Peptide hydrolases that have a cysteine involved in the catalytic process. This group of enzymes is inactivated by sulfhydryl reagents.
PC00203	1.21.05.03.00	serine protease	One of a group of endoproteases from both animal and bacterial sources that share a common reaction mechanism based on formation of an acyl enzyme intermediate on a specific active serine residue.
PC00053	1.21.05.05.00	aspartic protease	Peptide hydrolases that have two aspartyl residues in the catelytic process.
PC00048	1.21.06.00.00	amylase	A group of amylolytic enzymes that cleave starch, glycogen, and related alpha-1,4-glucans.
PC00087	1.21.07.00.00	deacetylase	An enzyme that removes acetate from a molecule.
PC00088	1.21.08.00.00	deaminase	An enzyme that removes amino groups from compounds, producing ammonia in the process.
PC00196	1.21.09.00.00	pyrophosphatase	Enzymes that catalyze the hydrolysis of diphosphate bonds, chiefly in nucleoside di- and triphosphates. They may liberate either a mono- or diphosphate.
PC00110	1.21.10.00.00	glycosidase	An enzyme that breaks up and degrades complex sugar subunits of a polysaccharide such as starch or sucrose into simple ones, such as glucose or fructose.
PC00108	1.21.11.00.00	glucosidase	Enzymes that hydrolyze o-glucosyl-compounds.
PC00104	1.21.12.00.00	galactosidase	One of a class of enzymes that cuts the glycosidic bond between the sugar galactose and another sugar molecule (of a different type than galactose).
PC00144	1.22.00.00.00	lyase	Enzymes that either strip a group from a molecule to form a double bond or add a group to a double bond.
PC00044	1.22.01.00.00	aldolase	An enzyme that catalyses an aldol condensation, i.e. a base-catalyzed addition reaction of two aldehydes or an aldehyde and a ketone to form an aldol (an organic compound that is both an aldehyde and an alcohol) and its reversal.
PC00091	1.22.02.00.00	dehydratase	Enzymes that remove hydroxyl groups from compounds, producing water in the process.
PC00120	1.22.03.00.00	hydratase	Enzymes that add hydroxyl groups to compounds, using water in the process.
PC00089	1.22.04.00.00	decarboxylase	Enzymes that remove carboxyl groups from compounds, producing carbonate in the process.
PC00079	1.22.05.00.00	cyclase	Enzymes responsible for converting a linear molecule into a cyclic molecule, such as a nucleoside triphosphate to cyclic nucleoside monophosphate.
PC00043	1.22.05.01.00	adenylate cyclase	An enzyme that is responsible for catalyzing the synthesis of adenosine 3', 5' cyclic monophosphate from adenosine 5' triphosphate.
PC00114	1.22.05.02.00	guanylate cyclase	An enzyme that is responsible for catalyzing the synthesis of guanosine 3', 5' cyclic monophosphate from guanosine 5' triphosphate.
PC00135	1.23.00.00.00	isomerase	A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.
PC00096	1.23.01.00.00	epimerase/racemase	Enzymes that catalyze inversion of the configuration around an asymmetric carbon in a substrate having one (racemase) or more (epimerase) center(s) of asymmetry (EC5.1).
PC00160	1.23.04.00.00	mutase	An enzyme that catalyzes the switching of functional groups on a molecule.
PC00142	1.24.00.00.00	ligase	A class of enzymes that catalyze the formation of a bond between two substrate molecules, coupled with the hydrolysis of a pyrophosphate bond in ATP or a similar energy donor.
PC00012	1.24.01.00.00	DNA ligase	An enzyme that seals nicks in one strand of double stranded DNA, by forming a phosphodiester linkage between a free 3 prime OH and 5 prime phosphate groups of two adjacent nucleotide residues.
PC00234	1.24.02.00.00	ubiquitin-protein ligase	An enzyme that couples ubiquitin to protein by a peptide bond between the C-terminal glycine of ubiquitin and a-amino groups of lysine residues in the protein.
PC00047	1.24.03.00.00	aminoacyl-tRNA synthetase	Any of the group of ligases that catalyzes the ATP-driven formation of a bond between an amino acid and a tRNA.   Also called aminoacyl-tRNA ligase.
PC00090	1.25.00.00.00	defense/immunity protein	A specific protein substance that is produced to take part in various defense and immune responses of the body.
PC00078	1.25.01.00.00	complement component	One of 20 distinct serum proteins that is the effector of immune cytolysis.
PC00149	1.25.02.00.00	major histocompatibility complex antigen	A set of plasmalemmal glycoproteins on the surface of all nucleated cells that are crucial for T-cell recognition of antigens.  They are the major antigens responsible for tissue recognition. There are two classes of histocompatibility antigens: Class I and Class II.
PC00051	1.25.03.00.00	antibacterial response protein	A peptide, which is usually produced by insects, that has antibacterial function.
PC00123	1.25.04.00.00	immunoglobulin	A specific protein substance that is produced by plasma cells to aid in fighting infection by taking part in various immune responses of the body to bacteria or foreign substances.
PC00124	1.25.05.00.00	immunoglobulin receptor superfamily	A receptor that contains an immunoglobulin domain.  It is often involved in immune response.  Some of the common members in this category are T cell receptors and IgG receptors.
PC00150	1.26.00.00.00	membrane traffic protein	A protein that is located on an intracellular vesicle membrane, and is responsible for the docking or fusion of the vesicle to the cytoplasma membrane.
PC00235	1.26.01.00.00	vesicle coat protein	A protein that is found in the secretory vesicle membrane.
PC00034	1.26.02.00.00	SNARE protein	A protein responsible for fusion of vesicle membrane and the plasma membrane, so as to release the content of the vesicle to the extracellular environment.
PC00151	1.26.03.00.00	membrane trafficking regulatory protein	A protein that regulates the release of secretory vesicle.
PC00072	1.27.00.00.00	chaperone	A cytoplasmic protein that binds to nascent or unfolded polypeptides and ensures correct folding or transport.
PC00073	1.27.01.00.00	chaperonin	Subset of chaperone proteins found in prokaryotes, mitochondria and plastids.
PC00026	1.27.02.00.00	Hsp60 family chaperone	Hsp60 (GroEL/GroES complex in E. coli) is a mitochondrial chaperonin that is typically held responsible for the transportation and refolding of proteins from the cytoplasm into the mitochondrial matrix. In addition to its role as a heat shock protein, HSP60 functions as a chaperonin to assist in folding linear amino acid chains into their respective three-dimensional structure.
PC00027	1.27.03.00.00	Hsp70 family chaperone	Widely distributed group of conserved heat-shock proteins of average weight 70 kD (DnaK in E. coli). Possess ATP binding domains and may be involved in protein folding or export.  
PC00028	1.27.04.00.00	Hsp90 family chaperone	Widely distributed group of conserved heat-shock proteins of average weight 90 kD (HtpG in E. coli). Exact function unknown, but are found associated with steroid hormone receptors and tyrosine kinase oncogene products. May also bind actin and tubulin.
PC00025	1.27.05.00.00	Hsp100 family chaperone	Hsp100 (Clp family in E. coli) proteins form large hexameric structures with unfoldase activity in the presence of ATP. These proteins are thought to function as chaperones by processively threading client proteins through a small 2 nm pore, thereby giving each client protein a second chance to fold.
PC00237	1.28.00.00.00	viral protein	A protein specific to a virus.
PC00236	1.28.01.00.00	viral coat protein	A protein that is a component of the outer coat of a virus (called the capsid).
PC00226	1.29.00.00.00	transmembrane receptor regulatory/adaptor protein	An intracellular protein that interacts with a transmembrane receptor, serving as either a regulator or adaptor to the receptor.
PC00211	1.30.00.00.00	structural protein	Extracellular proteins that form a structure for an organ or organism, such as the cuticle.
PC00161	1.30.01.00.00	myelin protein	Proteins found in the myelin sheath, which wraps around the nerve fibers serving as an insulator in both central and peripheral nervous system.
PC00210	1.31.00.00.00	storage protein	A protein that stores nutrients.  Usually these are serum or milk proteins.
PC00212	1.32.00.00.00	surfactant	A surface active agent, the best known example of which is the lung surfactant that renders the alveolar surfaces hydrophobic and prevents the lung filling with water by capillary action.