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Cytosolic and membrane-bound types of GST are encoded by 2 different supergene families. There are 8 classes of the soluble cytoplasmic mammalian GST: alpha, kappa, mu, omega, pi, sigma, theta and zeta. The mu class of enzymes functions in the detoxification of electrophilic compounds, including carcinogens, therapeutic drugs, environmental toxins and products of oxidative stress, by conjugation with glutathione. The genes encoding the mu class of enzymes are arranged in a gene cluster on chromosome 1p13.3 and aare highly polymorphic. These genetic differences can change an individual's resistance to carcinogens and toxins as well as affect the toxicity and efficacy of certain drugs. Null mutations of this class mu gene have been linked with the rise in a number of cancers.

D-lactate dehydrogenase (ldha) is a member of the D-isomer specific 2-hydroxyacid dehydrogenase family. In enzymology, an ldha (cytochrome) is an enzyme which catalyzes the chemical reaction. Therefore, the 2 substrates of the ldha enzyme are (D)-lactate and ferricytochrome c, whereas its 2 products are pyruvate and ferrocytochrome c.

GMDS is a member of the GDP-mannose 4,6-dehydratase family. GMDS uses NADP as a cofactor to catalyze the conversion of GDP-mannose to GDP-4-keto-6-deoxymannose. Defects in the gene encoding GMDS cause TRAIL (tumor necrosis factor-related apoptosis-inducing ligand)-induced apoptosis.

Adenosylmethionine decarboxylase proenzyme (AMD1) is synthesized originally as an inactive proenzyme. Putrescine stimulates both the proenzyme processing and the catalytic activity. The catalytic activity is inhibited by iodoacetic acid. The active enzyme formation entails a self-maturation process in which the active site pyruvoyl group is produced from an internal serine residue using an autocatalytic post-translational modification.

PECR is the main enzyme for a projected peroxisomal chain elongation pathway and is primarily expressed in kidney and liver.

PNMT is an enzyme located in the adrenal medulla and it catalyzes the final step of the catecholamine biosynthesis pathway. PNMT has beta-carboline 2N-methyltransferase activity. PNMT takes part in regulating epinephrine production. Glucocorticoid receptors form multimers of PNMT independent of the DNA binding domain. PNMT expression is regulated late in mouse gestation by AP2-alpha and glucocorticoids.

POLR2J2 belongs to the RNA polymerase II subunit 11 gene family, that includes 3 genes in a cluster on chromosome 7q22.1 and a pseudogene on chromosome 7p13. DNA directed RNA polymerase II polypeptide J family encodes a subunit of RNA polymerase II, the polymerase which is responsible for synthesizing messenger RNA in eukaryotes. This locus produces multiple, otherwise spliced transcripts which express isoforms with distinct C-termini compared to DNA directed RNA polymerase II polypeptide J. Most or all variants are spliced to include additional non-coding exons at the 3' end that makes them candidates for nonsense-mediated decay (NMD). Therefore, it is unknown if this locus expresses a protein or proteins in vivo.

POGLUT1 is a homologue of Rumi from Drosophila, an endoplasmic reticulum (ER)-retaining glucosyltransferase which catalyzes the transfer of glucose and xylose from UDP-glucose and UDP-xylose, respectively, to EGF repeats on the consensus sequence C-X-S-X-P-C. POGLUT1 positively regulates Notch signaling without affecting Notch ligand binding.

GMPR2 is the single known metabolic step by which guanine nucleotides can be transformed to the pivotal precursor of both adenine and guanine nucleotides. GMPR2 catalyzes the permanent NADPH-dependent reductive deamination of GMP to IMP, and is involved in re-utilization of free intracellular bases and purine nucleosides.

AURKA (Aurora Kinase A) belongs to the mitotic serine/threonine kinases family. AURKA is a cell cycle-regulated kinase which may be involved in microtubule formation and/or stabilization at the spindle pole during chromosome segregation. AURKA is found at the centrosome in interphase cells and at the spindle poles in mitosis. Since the AURKA expression is cell-cycle regulated, it is low in G1/S, it accumulates during G2/M, and it decreases rapidly after. AURKA is involved in important processes during mitosis and meiosis whose proper function is essential for healthy cell proliferation. In addition, AURKA plays an essential role in tumourigenesis and is overexpressed in various types of cancers. AURKA is strongly expressed in the testis, colon, ovarian, prostate, neuroblastoma, breast and cervical cancer cell lines and weakly in skeletal muscle, thymus and spleen. AURKA interacts with its substrates BORA and ARHGEF2, as well as with TACC1 and CPEB1.
Defects in the AURKA gene cause numerical centrosome aberrations including aneuploidy. AURKA overexpression has been linked to chromosomal instability in colorectal cancer. AURKA expression may have a prognostic significance in ovarian carcinoma.

Cathepsin S (CTSS) belongs to the peptidase C1 family. CTSS is a lysosomal cysteine proteinase that participates in the degradation of antigenic proteins to peptides for presentation on MHC class II molecules. CTSS functions as an elastase over a broad pH range in alveolar macrophages.

Membrane-bound & Cytosolic forms of GST are encoded by 2 separate supergene families. These enzymes function in the detoxification of electrophilic compounds, including carcinogens, therapeutic drugs, environmental toxins and products of oxidative stress, by conjugation with glutathione. There are 8 different classes of soluble cytoplasmic mammalian GST: alpha, kappa, mu, omega, pi, sigma, theta and zeta. The GSTA1 is found in a cluster mapped to chromosome 6, and is highly expressed in the liver. GSTA1 protects the cells from reactive oxygen species.

Phosphomannomutase 2 (PMM2) is a member of the eukaryotic PMM family. Phosphomannomutase 2 is involved in the synthesis of the GDP-mannose and dolichol-phosphate-mannose required for a number of critical mannosyl transfer reactions. PMM2 catalyzes the isomerization of mannose 6-phosphate to mannose 1-phosphate. PMM2 mutations are linked to congenital disorders of glycosylation (CDG)-Ia, an autosomal recessive disorder characterized by central nervous system dysfunction and multiorgan failure.

N-alpha-acetyltransferase 30 (NAA30) is catalytic subunit of the N-terminal acetyltransferase C (NatC) complex. NAA30 catalyzes acetylation of the N-terminal methionine residues of peptides beginning with Met-Leu-Ala and Met-Leu-Gly. In addition, NAA30 is essential for the lysosomal localization and function of ARL8B. The disease Eastern equine encephalitis has been associated with NAA30.

Avidin is a tetrameric protein of 4 identical subunits (homotetramer) which can bind to biotin with a high degree of affinity and specificity. The estimated molecular weight of Avidin in its tetrameric form is between 66-69 kDa. Avidin is produced in the oviducts of birds, reptiles and amphibians and is subsequently deposited in the whites of their eggs. In the chicken egg white, avidin makes up roughly 0.05% of total protein (approximately 1.8 mg per egg). 10% of Avidin’s molecular weight is ascribed to carbohydrate content which is composed of 4-5 mannose and 3 N-acetylglucosamine residues. Avidin has at least three distinctive oligosaccharide structural type which are similar in structure and composition. The dissociation constant (KD) of avidin is approximately 10-15M, making it one of the strongest known non-covalent bonds.

SUMF1 is a part of the SUMF protein family. SUMF1 catalyzes the hydrolysis of sulfate esters by oxidizing a cysteine residue in the substrate sulfatase to an active site 3-oxoalanine residue called C-alpha-formylglycine. Mutations in this gene will cause multiple sulfatase deficiency meaning a lysosomal storage disorder.

E.Coli Acetate Kinase, also knowns as ACKA, catalyzes the formation of acetyl phosphate from acetate and ATP and also catalyzes the reverse reaction. ACKA takes part in synthesis of various ATP formed catabolically during anaerobic growth of the organism.

DNA polymerase beta (POLB) is a member of the DNA polymerase type-X family. In eukaryotic cells, POLB performs base excision repair necessary for DNA maintenance, replication, recombination, and drug resistance. POLB has 2 separate domains; the larger is the polymerase domain itself, whereas a small basic N-terminal domain contains an AP lyase activity which excises the abasic sugar-phosphate residue at the strand break. POLB fills single nucleotide gaps in DNA produced by the base excision repair pathway of mammalian cells. POLB overexpression, as seen in some human tumors, could convene an increase in spontaneous mutagenesis.

Threonyl-tRNA Synthetase is a member of the aminoacyl-tRNA synthetase family, key enzymes of protein biosynthesis which charge tRNA molecules with the respective amino acids. This 83 kDa protein is an autoantigen recognized by PL-7 antibodies which occur in a subset of patients with polymyositis and dermatomyositis. Preliminary data suggest that PL-7 antibodies (similar to Jo-1 antibodies) indicate an increased risk for lung involvement, but this needs to be confirmed for a larger number of cases.

DUSP3 belongs to the dual specificity protein phosphatase subfamily which inactivates their target kinases by dephosphorylating both the phosphoserine/threonine and phosphotyrosine residues. DUSP3 negatively regulate members of the mitogen-activated protein kinase superfamily that are related to cellular proliferation and differentiation. DUSP3 is expressed in both breast and ovarian tissues and displays activity both for tyrosine-protein phosphate and serine-protein phosphate, but exhibits a strong preference toward phosphotyrosines, specifically dephosphorylates and inactivates ERK1 and ERK2.

The protein encoded by this gene is a member of the bone morphogenetic protein family which is part of the transforming growth factor-beta superfamily. The superfamily includes large families of growth and differentiation factors. Bone morphogenetic proteins were originally identified by an ability of demineralized bone extract to induce endochondral osteogenesis in vivo in an extraskeletal site. This particular family member plays an important role in the onset of endochondral bone formation in humans, and a reduction in expression has been associated with a variety of bone diseases, including the heritable disorder Fibrodysplasia Ossificans Progressiva. Alternative splicing in the 5' untranslated region of this gene has been described and three variants are described, all encoding an identical protein.

NQO1 belongs to the NAD(P)H dehydrogenase (quinone) family and encodes a cytoplasmic 2-electron reductase. NQO1 acts as an imperative part of cellular antioxidant defense by detoxifying quinines therefore preventing the formation of reactive oxygen species. It seems that NQO1 serves as a quinone reductase relating to conjugation reactions of hydroquinons involved in detoxification pathways in addition to biosynthetic processes such as the vitamin K-dependent gamma-carboxylation of glutamate residues in prothrombin synthesis. Altered NQO1 expression is seen in many tumors and also linked to Alzheimer’s disease. NQO1 gene mutations are linked to tardive dyskinesia which is an increased risk of hematotoxicity after exposure to benzene, and susceptibility to various forms of cancer.

DUSP21 is a member of the protein-tyrosine phosphatase family. DUSPs inactivate their target kinases by dephosphorylating both the phosphoserine/threonine and phosphotyrosine residuesb. DUSP21 is able to dephosphorylate single and diphosphorylated synthetic MAPK peptides, favoring the phosphotyrosine and diphosphorylated forms over phosphothreonine. DUSP21 is only expressed in testis where there are dephosphorylated phosphotyrosine residues in MAPK peptides.

tRNA aspartic acid methyltransferase 1 (TRDMT1) is a member of the C5-methyltransferase family. TRDMT1 specifically methylates cytosine 38 in the anticodon loop of tRNA(Asp). TRDMT1 is a protein responsible for the methylation of aspartic acid transfer RNA, particularly at the cytosine-38 residue in the anticodon loop. In addition, the TRDMT1 enzyme has residual DNA-(cytosine-C5) methyltransferase activity. TRDMT1 is expressed ubiquitously; however it has a higher expression in the testis, ovary and thymus and at much lower levels in the spleen, prostate, colon, small intestine, and peripheral blood leukocytes. Though similar in sequence and structure to DNA cytosine methyltransferases, the TRDMT1 gene is distinctive and extremely conserved in its function between taxa.