Search results

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.

Serine protease 28, also known as Prss28, is a member of the S1 serine proteinase family with a conserved Histidine-Aspartic Acid-Serine catalytic triad. Prss28 shows mixed substrate specificity which silences signaling through proteinase-activated receptors. Furthermore, Prss28 is involved with embryo hatching and its activity is vital for successful implantation.

Rnase P protein, AKA rnpA, is an important enzyme consisting of the C5 protein (which encoded by rnpA) and the catalytic M1 RNA (encoded by rnpB) subunits. rnpA is ribonucleoprotein that catalyzes the removal of the 50- leader elements of precursor tRNAs and generates the mature 50-end of tRNAs. This step is critical for theformation of functional tRNA molecules in bacteria, archaea and eukarya. More importantly, it has lately been established that RNase P is essential for the endonucleolytic separation of certain polycistronic tRNA transcripts such as valV valW, leuQ leuP leuV and secG leuU. Therefore, it was hypothesized that the essential function of RNase P might be related to the complete absence of a particular tRNAthat was dependent on the enzyme for initial separation from polycistronic transcripts.

STIP1 is an adaptor protein that mediates the functions of HSP70 & HSP90 in protein folding. STIP1 supports the transfer of proteins from HSP70 to HSP90 by binding together HSP90 and substrate-bound HSP70. STIP1 stimulates the ATPase activity of HSP70 and inhibits the ATPase activity of HSP90, suggesting that it regulates both the conformations and ATPase cycles of these chaperones. STIP1 genetic variations are involved in regulating corticosteroid response in asthmatic subjects with reduced lung function.

HSPA13 belongs to the heat shock protein 70 family and is related to microsomes. Members of this protein family take part in the processing of cytosolic and secretory proteins, in addition to the exclusion of denatured or incorrectly-folded proteins. HSPA13 is known to cooperate with PLIC-1 and PLIC-2, proteins which have a role in the signaling connection between the membrane receptors for thrombospondin and the cytoskeleton

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.

Gankyrin (proteasome 26S subunit) is a multicatalytic proteinase oncoprotein commonly overexpressed in most hepatocellular carcinomas. Proteasomes are found throughout eukaryotic cells at a high concentrations and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. Gankyrin interacts with S6 ATPase of the 19S regulatory particle of the 26S proteasome. Gankyrin is involved in theregulation of the phosphorylation of the retinoblastoma protein by CDK4, and to enhance the ubiquitinylation of p53 by MDM2. Gankyrin consists of 7 ankyrin repeats and is structurally similar to I kappa Bs. Gankyrin acts as a regulatory subunit of the 26s proteasome which is involved in the atp-dependent degradation of ubiquitinated proteins. Gankyrin is involved in progression of esophageal squamous cell carcinoma. gankyrin plays an oncogenic role especially in early stages of human epatocarcinogenesis. Gankyrin binds to NF-kappaB and suppresses its activity at the transcription level by modulating acetylation through SIRT1. Structural comparison between Gankyrin & p16(INK4A) identified numerous residues of gankyrin that are potentially important for CDK4 binding.

GSTT1 belongs to a superfamily of proteins which catalyze the conjugation of reduced glutathione to a variety of electrophilic and hydrophobic compounds. GSTT1 is one of the GSTs’ four main classes: alpha, mu, pi and theta (which includes GSTT1 and GSTT2). GSTT1 is involved in activation and detoxification reactions and catalyzes the conjugation of industrial chemicals, such as epoxybutane, ethylene oxides, halomethane with glutathione. GSTT1 is found in erythrocytes, at low levels in the liver as well as in Clara and ciliated cells at the alveolar/bronchiolar junction in the lung. The GSTT1 gene is deficient in 38% of the population. The GSTTI enzyme deficiency might influence the individual risk for development of acquired aplastic anemia and acute myeloid leukemia. The presence or absence of the GSTT1 gene is concurrent with GSST1+ (the conjugator) and GSTT1- (the non-conjugator) phenotypes correspondingly. The GSTT1+ phenotype is able to catalyze the glutathione conjugation of dichloromethane. GSTT1-null genotypes are seen as having a higher risk of developing leukoplakia. Germline genetic polymorphism in GSTT1 is linked to breast cancer.

Human Ubquitin Conjugating Enzyme 9 (Ubc9) is a member of the E2 family and is specific for the conjugation of SUMO to a variety of target proteins. SUMO conjugation to target proteins is mediated by a different, but analogous, pathway to ubiquitinylation. This E2 is unusual in that it interacts directly with protein substrates that are modified by sumolyation, and may play a role in substrate recognition. Ubc9 can mediate the conjugation of SUMO-1 to a variety of proteins including RanGAP1, I?B?, and PML without the requirement of an E3 ligase.

Cysteine Conjugate-Beta Lyase Cytoplasmic also known as CCBL1 is a member of the class-I pyridoxal-phosphate-dependent aminotransferase family. CCBL1 catalyzes the irreversible transamination of the L-tryptophan metabolite L-kynurenine to form kynurenic acid (KA) it also metabolizes the cysteine conjugates of certain halogenated alkenes and alkanes to form reactive metabolites. Furthermore, CCBL1 catalyzes the beta-elimination of S-conjugates and Se-conjugates of L-(seleno) cysteine, resulting in the cleavage of the C-S or C-Se bond.

Cytochrome b5 isoform 1 (CYB5A) is a member of the cytochrome b5 family. CYB5A is a membrane bound hemoprotein which functions as an electron carrier for several membrane bound oxygenases. Defects in the CYB5A gene are the cause of methemoglobinemia CYB5A-related (METHB-CYB5A), which is a form of methemoglobinemia (a hematologic disease characterized by the presence of excessive amounts of methemoglobin in blood cells, resulting in decreased oxygen carrying capacity of the blood, cyanosis and hypoxia).

Protein Phosphatase 1D (PPM1D) belongs to the PP2C family of Ser/Thr protein phosphatases whose members are negative regulators of cell stress response pathways. PPM1D is induced by tumor suppressor protein TP53/p53 in response to multiple environmental stresses. PPM1D is a negative regulator of the activity of p38 MAP kinase through which it reduces the phosphorylation of p53 and suppresses p53-mediated transcription and apoptosis. PPM1D is located in a chromosomal area which enlarges in breast cancer.

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.

TatD DNase Domain Containing 1, also known as TATDN1, is a protein coding gene which is a part of the TatD DNase family. TATDN1 which is a deoxyribonuclease binds two divalent metal cations per subunit.

CRABP1 is a member of special carrier proteins for members of the vitamin A family. It is believed that CRABP1 has an essential role in retinoic acid-mediated differentiation and proliferation processes. Though, CRABP1 is structurally similar to the cellular retinol-binding proteins, it binds only retinoic acid at specific sites within the nucleus, which may contribute to vitamin A-directed differentiation in epithelial tissue. CRABP1 is constitutively expressed and is thought to have different functions in the cell than the related CRABP2. CRABP1 forms a beta-barrel structure which accommodates hydrophobic ligands in its interior. Loss of CRABP1 function as a result of hypermethylation of its promoter leads to pathogenesis of papillary thyroid carcinoma. Furthermore, frequent methylation-associated silencing of CRABP1 is linked to esophageal squamous-cell carcinoma.

Methionine sulfoxide reductase B1 (SEPX1 or MSRB1), is a selenoprotein that contains a selenocysteine (Sec) residue at its active site. The selenocysteine is encoded by the UGA codon that usually signals translation termination. SEPX1 is a member of the methionine sulfoxide reductase B (MsrB) family, and is expressed in an assortment of adult and fetal tissues. MSRs (Methionine sulfoxide reductases) catalyze the reduction of free and protein-bound methionine sulfoxides to corresponding methionines. The oxidation of methionine by ROS creates a diastereomeric mixture of methionine-S-sulfoxide (Met-S-SO) and methionine-R-sulfoxide (Met-R-SO). Two separate enzyme families evolved for reduction of these sulfoxides, with methionine-S-sulfoxide reductase (MsrA) being stereospecific for Met-S-SO and methionine-R-sulfoxide reductase (MsrB) for Met-R-SO.

Probable tRNA (His) guanylyltransferase (THG1L) is a member of the tRNA (His) gyanylytransferase family. THG1L which is localized to the cytoplasm also found adjacent to the nuclear membrane and expressed in various tissues, including liver and lung. THG1L is expressed in a cell cycle-dependent manner and may be involved in cell cycle progression and cell proliferation. THG1L adds a GMP to the 5'-end of tRNA(His) after transcription and RNase P cleavage. This step is vital for accurate recognition of the tRNA and for the fidelity of protein synthesis. Upon DNA damage, THG1L is phosphorylated, presumably by ATM or ATR.

Protein Phosphatase 1, Regulatory Subunit 3B (PPP1R3B) is the catalytic subunit of the serine/theonine phosphatase, protein phosphatase-1. PPP1R3B, which is expressed both in liver and in skeletal muscle tissue, regulates glycogen synthesis in these tissues. PPP1R3B is involved in type 2 diabetes and maturity-onset diabetes of the young.

Ectonucleoside Triphosphate Diphosphohydrolase 6 or ENTPD6 is an enzyme, akin to E-type nucleotidases. E-type nucleotidases, for instance CD39, are responsible for extracellular nucleotides catabolism. ENTPD6 has four apyrase-conserved areas like all to E-type nucleotidases. Rather spliced transcript agents that codes various isoforms were discovered for the DNA segment.

Coproporphyrinogen Oxidase (CPOX) which is localized to the internal membrane space of erythrocytes takes part in the 6th phase of heme biosynthesis. CPOX catalyzes the oxidative decarboxylation of propionic acid side chains of rings A and B of coproporphyrinogen III. Mutations in human CPOX gene forecast the clinical result of the disease, with either hepatic hereditary coproporphyria or hematological manifestations of erythropoietic harderoporphyria.

ACTN1 encodes a nonmuscle, cytoskeletal, alpha actinin isoform and maps to the same site as the structurally similar erythroid beta spectrin gene. Alpha actinins belong to the spectrin gene superfamily which represents a diverse group of cytoskeletal proteins, including the alpha and beta spectrins and dystrophins. Alpha actinin is an actin-binding protein with multiple roles in different cell types. In nonmuscle cells, the cytoskeletal isoform is found along microfilament bundles and adherens-type junctions, where it is involved in binding actin to the membrane. In contrast, skeletal, cardiac, and smooth muscle isoforms are localized to the Z-disc and analogous dense bodies, where they help anchor the myofibrillar actin filaments.

Eukaryotic initiation factor 4A-III (EIF4A3) is a member of the DEAD box helicase family and eIF4A subfamily. DEAD box proteins, distinguished by the conserved motif Asp-Glu-Ala-Asp (DEAD), are putative RNA helicases. These proteins are involved in several cellular processes including alteration of RNA secondary structure, such as translation initiation, nuclear and mitochondrial splicing, and ribosome and spliceosome assembly. EIF4A3 is a part of a splicing-dependent multiprotein exon junction complex (EJC) accumulated at splice junction on mRNAs. Based upon their distribution patterns, some members of the DEAD box helicase family are thought to be involved in embryogenesis, spermatogenesis, and cellular growth and division.

Cytidine deaminase (CDA) is an enzyme that scavenges exogenous and endogenous cytidine and 2'-deoxycytidine for UMP synthesis. CDA is one of several deaminases responsible for maintaining the cellular pyrimidine pool. CDA also catalyzes the deamination of chemotherapeutic cytosine nucleoside analogs such as Ara-C and 5-azacytidine, which results in the loss of their cytotoxic and antitumor function. CDA can form homotetramers and is generally expressed in granulocytes. Mutations in the CDA gene are linked to decreased sensitivity to the cytosine nucleoside analogue cytosine arabinoside used in the treatment of certain childhood leukemias.

PDIA4 is an endoplasmic reticulum luminal protein that is a stress protein as well as a member of the protein disulfide isomerase family of proteins. PDIA4 participates in the catalysis of protein-S-S-bond rearrangement. PDIA4 and PDIA3 function as proteases, protein disulfide isomerases, phospholipases or an arrangement of these.