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Ribulose-phosphate 3-epimerase (RPE) is a member of the ribulose-phosphate 3-epimerase family. RPE is the enzyme which converts D-ribulose 5-phosphate into D-xylulose 5-phosphate in Calvin's reductive pentose phosphate cycle. Therefore, the RPE enzyme has one substrate, D-ribulose 5-phosphate, and one product, D-xylulose 5-phosphate. RPE participates in three metabolic pathways: pentose phosphate pathway, pentose and glucuronate interconversions, and carbon fixation.

Dual specificity phosphatase 18 (DUSP18) belongs to the dual-specificity phosphatase (DSP) family, which catalyzes dephosphorylation of phosphotyrosine and phosphothreonine residues. DUSP18 has a preferential enzymatic activity for phosphorylated tyrosine residues over threonine residues, in addition DUSP18 dephosphorylates p-nitrophenyl phosphate (pNPP) in vitro. Furthermore, DUSP18 is inhibited by iodoarectic acid and is activated by manganese ions. DUSP18 is extensively expressed with the highest levels in the liver, brain, ovary and testis.

Platelet-activating factor acetylhydrolase 2 cytoplasmic (PAFAH2) has a marked selectivity for phospholipids with short acyl chains at the sn-2 position. PAFAH2 may share a mutual physiologic function with the plasma-type enzyme.

HtrA2 also called Omi is a mammalian serine protease at high temperatures and has a chaperone activity at low temperature. The full-length HtrA2 is synthesized as a precursor protein and then targeted to the mitochondria where it is matured by the removal of N-terminal 133 residues. Mature HtrA2 consists of a putative transmembrane domain; an inhibitor of apoptosis protein (IAP)-binding motif; a single C-terminal PDZ domain that mediates protein-protein interactions. Recently, HtrA2 has known to contribute both to caspase-dependent and caspase-independent cell death.

Creatine Kinase MM is a cytoplasmic enzyme involved in energy homeostasis and is an important serum marker for myocardial infarction. The encoded protein reversibly catalyzes the transfer of phosphate between ATP and various phosphogens such as creatine phosphate. It acts as a homodimer in striated muscle as well as in other tissues, and as a heterodimer with a similar brain isozyme in heart. The encoded protein is a member of the ATP:guanido phosphotransferase protein family.

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.

STX12 is a member of the syntaxin family which are cellular receptors for transport of vesicles that take part in exocytosis in neutrophils. STX12 regulates protein transport from late endosomes and the trans-Golgi network and back. Additionally, STX12 cooperates with ABC1 (ATP-binding cassette transporter A1), which enables cellular release of cholesterol and choline-phospholipids to apoA-I (apolipoprotein A-I).

Cyclophilin-D is a member of the peptidyl-prolyl cis-trans isomerase (PPIase) family. PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and speeds up the protein folding. Cyclophilin-D possess PPIase activity and binds to the immunosuppressant cyclosporin-A. Cyclophilin-D is very well known that its overexpression suppresses the apoptosis in cancer cell. Cyclophilin-D suppresses apoptotic cell death by the use of mitochondrial hexokinase-2 dependent mechanism in cancer cells.

SUMO-activating enzyme subunit 2 (UBA2) belongs to a family of small and related proteins which can be enzymatically attached to a target protein by a post-translational modification process termed sumoylation. UBA2 is conjugated to various molecules in the presence of the SAE1/UBA2 SUMO-activating(E1) enzyme and the UBE2I/Ubc9 SUMO-conjugating(E2) enzyme. UBA2 represents a vital mechanism to protect neurons during episodes of cerebral ischemia.

GALE is an enzyme that participates as the third enzyme in the Leloir pathway of galactose metabolism. GALE is a homodimeric epimerase localized in bacterial, plant, and mammalian cells. GALE inhances the reverse chemical reaction, the conversion of UDP-glucose to UDP-galactose. UDP-galactose builds galactose-containing proteins and fats, which have a crucial part in chemical signaling, building cellular structures, transporting molecules, and producing energy.

Glutamine--Fructose-6-Phosphate Transaminase 1 (GFPT1) participates in the hexosamine pathway and controls the glucose fluidity into the hexosamine pathway. GFPT1 regulates the availability of precursors for N- and O-linked glycosylation of proteins. GFPT1 controls the circadian expression of clock genes ARNTL/BMAL1 and CRY1.

SHMT1 is a member of the SHMT family. SHMT1 is the cellular form of serine hydroxymethyltransferase, a pyridoxal phosphate-containing enzyme which catalyzes the reversible conversion of serine and tetrahydrofolate to glycine and 5 10-methylene tetrahydrofolate. In addition, SHMT1 specifically provides one-carbon units for thymidylate biosynthesis, reduces methylenetetrahydrofolate pools for S-adenosylmethionine (SAM) synthesis by synthesizing serine, sequesters 5-methyltetrahydrofolate and inhibits SAM synthesis.

Synaptic vesicle membrane docking and fusion is mediated by SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors) located on the vesicle membrane (v-SNAREs) and the target membrane (t-SNAREs). The assembled v-SNARE/t-SNARE complex consists of a bundle of four helices, one of which is supplied by v-SNARE and the other three by t-SNARE. For t-SNAREs on the plasma membrane, the protein syntaxin supplies one helix and the protein encoded by this gene contributes the other two. Therefore, SNAP25 product is a presynaptic plasma membrane protein involved in the regulation of neurotransmitter release. The synaptosomal-associated protein (SNAP-25) is an essential component of the core complex that mediates presynaptic vesicle trafficking. Thus, SNAP-25 is directly involved in the release of neurotransmitters.

NNMT is part of the family of transferases, especially those transferring one-carbon group methyltransferases. NNMT is mostly expressed in the liver, and a lower expression is seen in the kidney, lung, skeletal muscle, placenta and heart. NNMT catalyzes the N-methylation of nicotinamide and other pyridines to form pyridinium ions. This activity is significant for biotransformation of many drugs and xenobiotic compounds. NNMT is accountable for the enzymatic activity which uses S-adenosyl methionine as the methyl donor. NNMT expression is related with tumor stage and DFS time in hepatocellular carcinoma cases. NNMT is a good candidate as a tumor marker of various kinds of cancers. NNMT serum levels have significance in the premature detection and in the management of patients with colorectal cancer.

PGAM1 is part of the phosphoglycerate mutase family. PGAM1 is an essential component of glucose and 2,3-BPGA (2,3-bisphosphoglycerate) metabolism and catalyzes the reversible reaction of 3-phosphoglycerate (3-PGA) to 2-phosphoglycerate (2-PGA) in the glycolytic pathway. PGAM1 is a dimeric enzyme containing, in different tissues, different proportions of a slow-migrating muscle (MM) isozyme, a fast-migrating brain (BB) isozyme, and a hybrid form (MB). PGAM1 mutations lead to muscle phosphoglycerate mutase deficiency, a.k.a. glycogen storage disease X.

GSTT2 belongs to the glutathione s-transferase (GST) family of proteins. There are eight GST proteins families, named alpha, kappa, mu, omega, pi, sigma, theta and zeta. Each one of the GST families has several proteins with different functions throughout the cell. The theta type members GSTT1 and GSTT2 have a 55% aa sequence homology and hold a vital role in human carcinogenesis. The theta genes are structurally similar – each has five exons with identical exon/intron boundaries.

G6PD is the rate-limiting enzyme of the pentose phosphate pathway, a metabolic pathway that supplies reducing energy to cells by maintaining the level of NADPH. G6PD converts glucose-6-phosphate into 6-phosphoglucono-?-lactone and at the same time produces NADPH. The NADPH maintains the level of glutathione in these cells that helps protect the red blood cells against oxidative damage. G6PD deficiency causes acute hemolytic anemia, neonatal jaundice or acute hemolysis. G6PD is a cytosolic enzyme encoded by an X-linked gene whose main function is to produce NADPH, a crucial electron donor in the defense against oxidizing agents and in reductive biosynthetic reactions. G6PD produces pentose sugars for nucleic acid synthesis and is a main producer of NADPH reducing power.

Acid Phosphatase-6, also known as ACP6 is Hydrolyzes lysophosphatidic acid (LPA) which contains a medium length fatty acid chain to the corresponding monoacylglycerol. ACP6 shows highest activity with lysophosphatidic acid which contains myristate (C14:0), monounsaturated oleate (C18:1) or palmitate (C16:0), and lower activity with C18:0 as well as C6:0 lysophosphatidic acid.

Haloacid dehalogenase-like hydrolase domain-containing protein 1A (HDHD1A) is a member of the adiponutrin family. HDHD1A is interesting because it is an X-linked gene that escapes X-inactivation. HDHD1A is particularly important in the perception of human X chromosome structural organization as well as the mechanism of X-inactivation.

MMP28, which belongs to the matrix metalloproteinase (MMP) family, takes part in the breakdown of extracellular matrix for both normal physiological processes, such as embryonic development, reproduction and tissue remodeling, and disease processes, like asthma and metastasis. MMP28 is a secreted enzyme which degrades casein. MMP28 participates in tissue homeostasis and in wound repair.

Osteostat is the cytokine that binds to TNFRSF18/AITR/GITR and is important for interactions between activated T-lymphocytes and endothelial cells and may modulate T-lymphocyte survival in peripheral tissues. Osteostat is expressed at high levels in the small intestine, ovary, testis, kidney and endothelial cells after stimulation by lipopolysaccharides.
Osteostat protein is detectable in human microvascular EC and is highly up-regulated by IFN-alpha and IFN-beta. Osteostat inhibit differentiation of osteoclasts from monocytic precursor cells. Osteostat suppresses the early stage of osteoclastogenesis via inhibition of macrophage colony-stimulating factorinduced receptor activator of NF-kappaB (RANK) expression in the osteoclast precursor cells. Osteostat does not inhibit lipopolysaccharide-induced RANK expression in monocytes and dendritic cells, or activation-induced RANK expression in T cells. Osteostat is a novel regulator of osteoclast generation and substantiate the major role played by the endothelium in bone physiology.