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The Casein kinase 2 (EC2.7.11.1) is a serine/threonine-selective protein kinasethat is a tetramer of two alpha subunits and two beta subunits. The alpha subunits have the catalytic kinase domain. Casein kinase 2 has been implicated in cell cyclecontrol, DNA repair, regulation of the circadian rhythmand other cellular processes.
Casein kinase 2 activity has been reported to be activated following Wnt signaling pathwayactivation. A Pertussis toxin-sensitive G proteinand Disheveled appear to be an intermediary between Wnt-mediated activation of the Frizzled receptor and activation of casein kinase 2.
Mice that lack casein kinase 2 alpha prime have a defect in the morphology of developing sperm.

ILK1 (Integrin-linked kinase) is a serine/threonine protein kinase, containing 4 ankyrin-like repeats. ILK1 regulates a number of biological properties which include: anchorage-independent cell cycle progression, tumor cell invasion and apoptosis. ILK1 can also be implicated in mediating cell architecture, adhesion to integrin substrates and anchorage-dependent growth in epithelial cells. Furthermore, ILK1 phosphorylates beta-1 and beta-3 integrin subunit on serine and threonine residues, but also AKT1 and GSK3B.
ILK1 interacts with the cytoplasmic domains of integrin ?1 and ?3 subunits in addition to several adaptors and signaling proteins, it also acts as a proximal receptor kinase regulating integrin-mediated signal transduction. ILK1 is a focal adhesion protein part of the complex ILK-PINCH. This complex is deemed to be one of the convergence points of integrin- and growth factor-signaling pathway. ILK1 is stimulated rapidly but briefly by both cell fibronectin interactions in a PI3-K-dependent manner, probably through the binding of PtdIns(3,4,5)P3 with a PH-like domain of ILK.
ILK1 over-expression has been documented in a wide variety of human malignancies.

TOP1 is an important nuclear enzyme that interconverts supercoiled DNA to the necessary topological conformations for standard DNA replication and transcription. TOP1 is the target antigen for TOP1 autoantibodies. TOP1 antibodies are a specific marker in scleroderma patients (specificity 98-100%) and are related with the existence of diffuse skin involvement and pulmonary fibrosis. In human tissues top1 enzyme is primarily synthesized as a protein with a molecular weight of 100-kDa. Most of this precursor is then proteolytically processed to a 70-kDa size, from which the TOP1 antigen has derived its name.

Thyroid Peroxidase (TPO) represents one of the main autoantigenic targets in autoimmune thyroid disease of humans. Its identity with the formerly so-called `microsomal antigen` has been shown several years ago. As an integral membrane glycoprotein it is restricted to the apical plasma membrane of the follicular epithelial cells and comprises two identical subunits of approx. 100 kDa molecular weight. The hemoprotein TPO plays a key role in the thyroid hormone biosynthesis by catalysing both the iodination of tyrosyl residues and the coupling of iodotyrosyl residues in thyroglobulin (TG) to form precursors of the thyroid hormones T4 and T3.

Histidyl-tRNA synthetase (HARS) functions to catalyze the aminoacylation of tRNAs by their corresponding amino acids. HARS is a member of the class II family of aminoacyl-tRNA synthetases. HARS is responsible for the synthesis of histidyl-transfer RNA, which is vital for the incorporation of histidine into proteins. HARS is a frequent target of autoantibodies in the human autoimmune disease polymyositis/dermatomyositis.

Serine/threonine/tyrosine-interacting protein (STYX) is a member of the protein-tyrosine phosphatase family. STYX contains a Gly residue instead of a conserved Cys residue in the dsPTPase catalytic loop which makes it catalytically inactive as a phosphatase. On the other hand, the binding pocket is adequately preserved to bind phosphorylated substrates, and may protect them from phosphatases. STYX may have a role in spermiogenesis. STYX is a possible pseudophosphatase.

Glutathione reductase (Gor) is a member of the class-I pyridine nucleotide disulfide oxidoreductase family. The main role of the Gor protein is to uphold high levels of reduced glutathione in the cytosol. With the associated oxidation of NADPH, Gor transforms oxidized glutathione to the reduced form. The active site of the Gor protein is a redox-active disulfide bond.

Acyl CoA dehydrogenase is the enzymeused to catalyzethe first step of ?-oxidationin Fatty acid metabolism.
Acyl-coenzyme A (CoA) dehydrogenases (ACADs) are a family of mitochondrial enzymes that catalyze the first dehydrogenation step in the bets-oxidation of fatty acyl-CoA derivatives. Several human ACADs exist and all ACADs catalyze the same initial dehydrogenation of the substrate at the beta-carbon atom and require electron transfer flavoprotein as an alectron acceptor. The predicted 415-amino acid ACAD8 protein contains many of the residues conserved in most other ACADs, including an active site glutamic acid residue and residues important for tetramer formation.

ACOT11 belongs to the acyl-CoA thioesterase family which catalyses the transformation of activated fatty acids to the equivalent non-esterified fatty acid and coenzyme A. Expression of a mouse homolog in brown adipose tissue is induced by low temperatures and inhibited by high temperatures. Obesity-resistant mice demonstrated High levels of expression compared with obesity-prone mice, indicating BFIT takes part in acyl-CoA thioesterase 11 in obesity. BFIT has acyl-CoA thioesterase activity towards medium (C12) and long-chain (C18) fatty acyl-CoA substrates.

Acyl-CoA Thioesterase 7 (ACOT7) belongs to the acyl coenzyme family. ACOT7 hydrolyzes the CoA thioester of palmitoyl-CoA and other long-chain fatty acids. Decreased expression of the ACOT7 protein may be linked to mesial temporal lobe epilepsy.

MMAB protein catalyzes the last step in the conversion of vitamin B(12) into adenosylcobalamin (AdoCbl), a vitamin B12 containing coenzyme for methylmalonyl-CoA mutase(MCM). Decreased MMAB activity leads to the inherited disorder vitamin B12 dependent methylmalonic aciduria linked to the cblB complementation group.

NANS is a 359 amino acid protein that contains one AFP (antifreeze proteins)-like domain and functions in the biosynthesis of sialic acids. The ubiquitously expressed NANS enzymatically catalyzes the H2O-dependent formation of N-acetylneuraminic acid (Neu5Ac) and 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN), both of which are sialic acids. NANS uses N-acetylmannosamine 6-phosphate as a substrate for Neu5Ac synthesis and mannose 6-phosphate as a substrate for KDN synthesis.

Biliverdin reductase A (BLVRA) is a member of the gfo/idh/mocA family. BLVRA is an enzyme that converts biliverdin to bilirubin, converting a double-bond between the second and third pyrrole ring into a single-bond. BLVRA reduces the gamma-methene bridge of the open tetrapyrrole, biliverdin IX alpha, to bilirubin with the simultaneous oxidation of a NADH or NADPH cofactor (Bilirubin + NAD(P)+ = biliverdin + NAD(P)H ).
BLVRA is a regulator for induction of activating transcription factor-2 and heme oxygenase-1. Furthermore, BLVRA enhances the role of HO-1 in cytoprotection and provides cytoprotection independent of heme degradation. In addition, Bilirubin while acting as a cytoprotective antioxidant is itself oxidized to biliverdin and subsequently recycled by biliverdin reductase back to bilirubin.

Carbonic anhydrases (CAs) are a large family of zinc metalloenzymes which catalyze the reversible hydration of carbon dioxide. These metalloenzymes participate in various biological processes, including respiration, calcification, acid-base balance, bone resorption, and the formation of aqueous humor, cerebrospinal fluid, saliva, and gastric acid. The metalloenzymes exhibit extensive diversity in tissue distribution and in their subcellular localization. Carbonic Anhydrase XI (CA11) is probably a secreted protein, nevertheless, drastic changes at active site residues completely conserved in CA isozymes with catalytic activity, make it unlikely that CA11 has carbonic anhydrase activity. CA11 shares properties in common with 2 other acatalytic CA isoforms, CA VIII and CA X. CA11 is amply expressed in the brain, and may have a general role in the central nervous system.

PGK1 is an X-linked enzyme that has a major role in the glycolytic pathway. PGK1 is a glycolytic enzyme which catalyzes the conversion of 1,3-diphosphoglycerate to 3-phosphoglycerate, generating an ATP molecule. PGK1 may also act as a cofactor for polymerase alpha. Defects in the PGK1 gene are usually associated with chronic hemolytic anemia, though it can be accompanied by either mental retardation or muscular disease (rhabdomyolysis). Overexpression of PGK1 and its signalling targets are possibly an expression-pathway in diffuse primary gastric carcinomas promoting peritoneal dissemination. It was shown that PGK1 is differentially expressed in the dorsolateral prefrontal cortex from patients with schizophrenia.

Fumarase is an enzymatic factor of Krebs cycle, which catalyzes the formation of L-malate from fumarate. Fumarase exists in both a cytosolic form and an N-terminal extended form, differing only in the translation start site used. The N-terminal extended form is aimed to the mitochondrion, where the removal of the extension results in the same form as in the cytoplasm. Fumarase is similar to a number of thermostable Class-2 fumarases and functions as a homotetramer. Mutations in the Fumarase gene causes fumarase deficiency and leads to progressive encephalopathy, cerebral atrophy and developmental delay. Fumarase enzyme is also thought to act as a tumor suppressor. Leydig cell tumors are caused by Fumarase mutations and represents one of the first reports of germline mutations in any type of adult testicular tumor.

Glutamate Decarboxylase 1 Isoform-1, also known as GAD1 iso1 belongs to the group II decarboxylase family. GAD1 iso1 encodes one of several forms of glutamic acid decarboxylase, and is identified as a major autoantigen in insulin-dependent diabetes. GAD1 iso1 is in charge for catalyzing the production of gamma-aminobutyric acid from L-glutamic acid. In addition, a pathogenic function for GAD1 iso1 has been shown in the human pancreas while it has been identified as an autoantigen & an autoreactive T cell target in insulin-dependent diabetes. GAD1 iso1 play a role in the stiff man syndrome. It has been shown that deficiency in this enzyme has led to pyridoxine dependency with seizures.

Phosphomevalonate kinase (PMVK) is a cytosolic enzyme. PMVK is expressed highly in the heart, liver, skeletal muscle, kidney and pancreas and slightly lower in the brain, placenta, and lung. PMVK catalyzes the conversion of mevalonate 5-phosphate into mevalonate 5-diphosphate in the fifth reaction of the cholesterol biosynthetic pathway. Induced by sterol, PMVK participates in isopentenyl diphosphate biosynthesis via the mevalonate pathway.

Human Ubquitin Conjugating Enzyme 7 (UbcH7) is a class I enzyme which functions in the stress response and the control of transcription factors. The enzyme is ubiquitously expressed with high levels of expression seen in adult muscle. UbcH7 mediates the selective degradation of short-lived and abnormal proteins and is highly homologous to UbcH5. It has been demonstrated to participate in the ubiquitinylation of p53, c-Fos and NF-?B. UbcH7 is one of two E2s (UbcH5 being the other) with which HECT domain proteins interact with UbcH7 being able to efficiently substitute for UbcH5 in E6-AP-dependent ubiquitinylation.

UBE2T is part of the E2 ubiquitin-conjugating enzyme family that participates in the protein degradation pathway. UBE2T catalyzes the ATP-dependent attachment of ubiquitin to target proteins, thus tagging them for subsequent destruction by the proteasome. UBE2T is an important factor of the Faconi anemia pathway of DNA damage repair and, upon self-inactivation, may negatively regulate the Faconi pathway.

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.

UMP-CMP kinase and deoxycytidylate kinase (CMPK1) is an enzyme which catalyzes the phosphoryl transfer from ATP to UMP, CMP and dCMP. This enzymatic reaction brings about the formation of ADP and the corresponding nucleoside diphosphate that are necessary for cellular nucleic acid synthesis. In addition, CMPK1 has a significant role in the activation of pyrimidine analogs, which are clinically useful anti-cancer and anti-viral drugs.

CPPED1 which is a part of the metallophosphoesterase superfamily takes part in glucose uptake by adipocytes. CPPED1 binds two divalent metal cations and is transactivated by the great envelope protein of the hepatitis B virus.

Matrix Metalloproteinase-13 (MMP-13) is an enzyme that is a member of the MMP extracellular protease family. Extracellular protease enzymes, by virtue of their broad substrate specificities1, play a role in both normal and disease states of tissue proliferation. Among the targets of MMP-13 are collagen, gelatin, entactin, pro-TNF-a, and chemokine SDF-11-4.
MMP-13 is found in its latent form as a 52-56 kDa glycosylated proenzyme. Upon cleavage the 22-46 kDa5 MMP-1 becomes active in extracellular matrix remodeling.
Because of the prominent role that MMP-1 plays in cell migration and metastasis, it is an important target for inhibition screening.