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Acyl-CoA Thioesterase 8 (ACOT8) is a group of enzymes which catalyze the hydrolysis of acyl-CoAs to the free fatty acid and coenzyme A (CoASH), granting the potential to regulate intracellular levels of acyl-CoAs, free fatty acids and CoASH. ACOT8 mediate Nef-induced down-regulation of CD4. ACOT8 contends with BAAT (Bile acid CoA: amino acid N-acyltransferase) for bile acid-CoA substrate (such as chenodeoxycholoyl-CoA). ACOT8 prefers medium-length fatty acyl-CoAs.

Phosphoglycolate phosphatase (PGP) is discovered in all tissues including red cells, lymphocytes and cultured fibroblasts (at protein level). PGP is most active in skeletal muscle and cardiac muscle. The catalytic activity of PGP is 2-phosphoglycolate + H2O = glycolate + phosphate. Diseases associated with PGP include tardive dyskinesia and polycystic kidney disease.

Sepiapterin Reductase is an aldo-keto reductase that catalyzes the NADPH-dependent reduction of pteridine derivatives and is essential in the biosynthesis of BH4. Mutations in Sepiapterin Reductase gene result in DOPA-responsive dystonia due to sepiaterin reductase deficiency defined by the presence of sustained involuntary muscle contractions, often leading to abnormal postures. Sepiapterin reductase is part of the short-chain dehydrogenase/reductase family which reduces exogenous carbonyl compounds as well as phenylpropanedione. Sepiapterin reductase is an important enzyme for the biosynthesis of tetrahydrobiopterin, an necessary cofactor for aromatic amino acid hydrolases together with tyrosine hydroxylase, the rate-limiting enzyme in DOPA synthesis.

Mitogen-activated protein kinase 1 (MAPK1) is also known as "extracellular signal-regulated kinase 2" (ERK2). Two similar (85% sequence identity) protein kinases were originally called ERK1 and ERK2. They were found during a search for protein kinases that are rapidly phosphorylated after activation of cell surface tyrosine kinasessuch as the epidermal growth factor receptor. Phosphorylation of ERKs leads to the activation of their kinase activity.
The molecular events linking cell surface receptors to activation of ERKs are complex. It was found that RasGTP-binding proteins are involved in the activation of ERKs. Another protein kinase, Raf-1, was shown to phosphorylate a "MAPK kinase", thus qualifying as a "MAPK kinase kinase". The MAPK kinase was named "MAPK/ERK kinase" (MEK).
Receptor-linked tyrosine kinases, Ras, Raf, MEK and MAPK could be fitted into a signaling cascade linking an extracellular signal to MAPK activation.
Transgenic gene knockoutmice lacking MAPK1 have major defects in early development.

Cathepsin D is synthesized as a 54kDa precursor, which is proteolytically processed to an intermediate 48kDa single chain, which matures into more stable 34kDa and 14kDa two chain form. It is an estrogen-regulated lysosomal protease that has been suggested to facilitate cancer cell migration and invasion by digesting the basement membrane, extracellular matrix, and xonnective tissue. Because of its mitogenic and proteolytic activities, it has been implicated as a prognostic marker in many tumor types. Cathepsin D is expressed in epithelial cells as well as in macrophages.

Eukaryotic elongation factor-2 kinase (EEF2K) is threonine kinase which regulates protein synthesis by means of controlling the rate of peptide chain elongation. Upon activation through a diversity of upstream kinases including AMPK or TRPM7, EEF2K phosphorylates the elongation factor EEF2 at a sole site, renders it unable to bind ribosomes and therefore inactive. In turn, the rate of protein synthesis is being reduced.

MMP-1 (interstitial collagenase) can break down a wide range of substrates including types I, II, III, VII, VIII, and X collagens as well as L-Selectin, pro-TNF, IL-1?, IGFBP-3, IGFBP-5, casein, gelatin, ?1 antitrypsin, myelin basic protein, pro-MMP2 and pro-MMP9. A significant function of MMP-1 is the degradation of fibrillar collagens in extracellular matrix remodeling. MMP-1 is expressed in fibroblasts, keratinocytes, endothelial cells, monocytes and macrophages. MMP1 can be divided into a number of distinct domains: a prodomain which is cleaved on activation, a catalytic domain containing the zinc binding site and a short hinge region with a carboxyl terminal domain. MMP1 is part of a cluster of MMP genes which localize to chromosome 11q22.3.

Kallikreins are a subgroup of serine proteases having various physiological functions. Numerous kallikreins are involved in carcinogenesis. Kallikrein-11 (KLK11) which is a multifunctional protease is 1 of the 15 kallikrein subfamily members found in a cluster on chromosome 19. KLK11 cleaves synthetic peptides after arginine but not lysine residues.

AK4 belongs to the adenylate kinase family of enzymes. AK4 protein is restricted to the mitochondrial matrix. Adenylate kinases regulate the adenine and guanine nucleotide structures in a cell by catalyzing the reversible transfer of phosphate group among these nucleotides. Hereditary mutations which cause AK4 deficiencies in erythrocytes have been associated to hemolytic anemia.

This E2 enzyme encodes for the human homolog of the yeast DNA repair gene RAD6, which is induced by DNA damaging agents. UBE2B can conjugate ubiquitin to histone H2A in an E3- independent manner in vitro, and is essential for the multi-ubiquitination and degradation of N-end rule substrates. Additionally, UBE2B may have a role in sepsis-induced muscle protein proteolysis and cancer-induced cachexia.

ST6GAL1 also known as ST6 Beta-Galactosamide Alpha-2,6-Sialyltranferase 1, is part of the glycosyltransferase family 29. ST6GAL1 is a type II membrane protein which catalyzes the transfer of sialic acid from CMP-sialic acid to galactose-containing substrates. Furthermore, ST6GAL1 is normally found in the Golgi however it can be proteolytically processed to a soluble form, ST6GAL1 is also involved in the generation of the cell-surface carbohydrate determinants as well differentiation antigens HB-6, CD75, and CD76.

PECI is an enzyme that localized to the peroxisomal matrix and encloses one ACB (acyl-CoA-binding) domain. PECI is expressed abundantly in liver, heart and skeletal muscle. PECI functions to catalyze the isomerization of both 3-cis and 3-trans double bonds into the 2-trans form in an array of enoyl-CoA species. PECI takes part in the beta-oxidation of unsaturated fatty acids.

Inositol monophosphatase1 (IMPA1) is responsible for the provision of inositol essential for synthesis of phosphatidylinositol and polyphosphoinositides. IMPA1 has a central role in the phosphatidylinositol signaling pathway by catalyzing the hydrolysis of inositol monophosphates. IMPA1 has been recognized as the pharmacological target for lithium action in the brain. The IMPA1 enzyme has a magnesium-dependent phosphatase activity and is inhibited by therapeutic concentrations of lithium. Inhibition of inositol monophosphate hydroylosis and ensuing depletion of inositol for phosphatidylinositol synthesis may perhaps explain the anti-manic and anti-depressive effects of lithium administered to treat bipolar disorder.

Carboxymethylenebutenolidase homolog (CMBL) is a cysteine hydrolase of the dienelactone hydrolase family which is highly expressed in the liver cytosol. CMBL is the human homolog of Pseudomonas dienelactone hydrolase, which is a protein that participates in the bacterial halocatechol degradation pathway. CMBL which preferentially cleaves cyclic esters activates medoxomil-ester prodrugs in which the medoxomil moiety is coupled with an oxygen atom. CMBL is inhibited by PCMB (p-chloromercuribenzoate) and is encoded by a gene which maps to human chromosome 5p15.2. CMBL can also activate beta-lactam antibiotics faropenem medoxomil and lenampicillin. CMBL is widely expressed, with the highest levels in the liver, followed by the kidney, small intestine and the colon.

MAT2B is part of the methionine adenosyltransferase family. MAT2B catalyzes the biosynthesis of S-adenosylmethionine from methionine and ATP. MAT2B is the regulatory beta subunit of MAT. MAT2B expression in hepatoma cell lines increases DNA synthesis and thus take part in cell proliferation.

DESI1 belongs to the DeSI family and contains 1 PPPDE peptidase domain. This protein is a protease which deconjugates SUMO1, SUMO2 and SUMO3 from some substrate proteins and has isopeptidase but not SUMO-processing activity. DESI1 desumoylates ZBTB46.

FARSB, also known as Phenylalanyl-TRNA Synthetase Beta is a member of the phenylalanyl-tRNA synthetase beta subunit family. FARSB is composed tetramer of two alpha and two beta subunits. In the presence of ATP, this tetramer is accountable for attaching L-phenylalanine to the terminal adenosine of the appropriate tRNA.

PLA2G7 is a secreted enzyme which catalyzes the degradation of platelet-activating factor to biologically inactive products. The PLA2G7 enzyme is produced by inflammatory cells and hydrolyzes oxidised phospholipids in LDL. In the blood, PLA2G7 goes mainly with LDL and less than 20% is coupled with HDL.
PLA2G7 is implicated in the development of atherosclerosis and is also a marker for cardiac disease. PLA2G7 might have a major physiologic effect in the presence of inflammatory bodily responses.
PLA2G7 alters the action of PAF (platelet-activating factor) by hydrolyzing the sn-2 ester bond to yield the biologically inactive lyso-PAF. PLA2G7 has specificity for substrates with a short residue at the sn-2 position. PLA2G7 is inactive against long-chain phospholipids.
PLA2G7 gene defects are the source of platelet-activating factor acetylhydrolase deficiency, which is a trait that is present in 27% of the Japanese population.

Inorganic pyrophosphatase (ppa) is a member of the Ppase family. PPA is an enzyme which catalyzes the conversion of one molecule of pyrophosphate to two phosphate ions. Since this is a highly exergonic reaction, it can therefore be coupled to unfavorable biochemical transformations in order to drive these transformations to completion. The role of the PPA enzyme is a critical one in the lipid metabolism (including lipid synthesis and degradation), calcium absorption and bone formation, DNA synthesis, as well as other biochemical transformations.

Aldolase C Fructose-Bisphosphate (ALDOC) belongs to the class I fructose-bisphosphate aldolase family. ALDOC is a glycolytic enzyme which catalyzes the reversible aldol cleavage of fructose-1,6-biphosphate and fructose 1-phosphate to dihydroxyacetone phosphate and either glyceraldehyde-3-phosphate or glyceraldehydes respectively. ALDOC is expressed exclusively in the hippocampus and Purkinje cells of the brain.

Enolase-phosphatase E1 (ENOPH1) belongs to the MasA family of the HAD (halo-acid dehalogenase)-like hydrolase superfamily. ENOPH1 is a bifunctional enzyme which demonstrates both phosphatase and atypical enolase activities. ENOPH1 has a significant role in the ubiquitous methionine salvage pathway which is a biochemical pathway found in all organisms that regulate methionine levels in the cell.

GOT2 is a pyridoxal phosphate-dependent enzyme which is found in cytoplasmic and inner-membrane mitochondrial forms, GOT1 and GOT2. GOT2 is invloved in amino acid metabolism and the urea and tricarboxylic acid cycles. The 2 enzymes are homodimeric and demonstrate close homology.

Mannoside Acetylglucosaminyltransferase 2 (MGAT2) is a golgi enzyme catalyzing an vital step in the conversion of oligomannose to complex N-glycans. MGAT2 enzyme has the characteristic glycosyltransferase domains: a short N-terminal cytoplasmic domain, a hydrophobic non-cleavable signal-anchor domain, and a C-terminal catalytic domain. MGAT2 gene mutations may lead to carbohydrate-deficient glycoprotein syndrome, type II.