Search results

Serum-and glucocorticoid-regulated kinase (SGK1) is a serine/threonine protein kinase and a member of the “AGC” subfamily, which includes protein kinases A, G, and C. The SGK1 protein has an imperative role in activating specific potassium, sodium and chloride channels, suggesting a participation in the regulation of processes such as cell survival, neuronal excitability, and renal sodium excretion. SGK1 is activated in vitro by PDK-1 (3-phosphoinositide-dependent protein kinase-1) and in vivo in reaction to signals which activate phosphatidylinositol (PI) 3-kinase.

The protein kinase A holoenzyme is a heterotetramer composed of two types of subunits: Catalytic and Regulatory. The Catalyticsubunit contains the enzyme's active site. It also contains a domain that binds ATP and a domain that binds the regulatory subunit. The Regulatory subunit consists oftwo molecules which bind one another in an anti-parallel orientation to form a homodimer; for type I subunits- this binding is covalent via disulfide bonds. This subunit also has has two domains that bind cyclic AMP, a domain that interacts with a catalytic subunit, and an "auto-inhibitory" domain that serves as a substrate or pseudosubstrate for the catalytic subunit. Regulatory subunits may also have biologic activity distinct from their role in modulating catalytic subunit activity. Regulatory subunits exist in two major forms, RI and RII, with each form having two subtypes designated alpha and beta. Each of the four isotypes of the regulatory subunit is encoded by a different gene. In addition, three isotypes of the catalytic subunit have been identified (alpha, beta and gamma). The different isotypes tend to have different distributions within cells and among tissues. Type I enzymes inhabit cytoplasmic, soluble fractions of the cell, whereas type II enzymes tend to associate with cellular membranes.

Set 7/9 is a histone methyltransferase (HMTase) that transfers methyl groups to Lys4 of histone H3, in complex with S-adenosyl-L-methionine (AdoMet). The methylation of lysine residues of histones plays a critical role in the regulation of chromatin structure and gene expression.
Acetylation, phosphorylation and methylation of the amino-terminal tails of histone are thought to be involved in the regulation of chromatin structure and function. The enzymes identified in the methylation of specific lysine residue on histones belong to the SET family with just one exception. Set7/9, unlike most other SET proteins, is exclusively a mono-methylase.

The 14-3-3 family of proteins plays a key regulatory role in signal transduction, checkpoint control, apoptotic and nutrient-sensing pathways. 14-3-3 proteins are highly conserved and ubiquitously expressed. There are at least seven isoforms that have been identified in mammals. The 14-3-3gamma, a subtype of the 14-3-3 family of proteins, was thought to be brain and neuron-specific. It has been shown to interact with RAF1 and protein kinase C, proteins involved in various signal transduction pathways.

Glutathione peroxidase 1 (GPX1) is a member of the glutathione peroxidase family, consisting of 8 identified glutathione peroxidases (Gpx1-8) in humans. Glutathione peroxidase serves in the detoxification of hydrogen peroxide, and is one of the most vital antioxidant enzymes in humans. The GPX1 is a component of the enzymatic antioxidant defense, preventing oxidative damage to DNA, proteins and lipids by detoxifying hydrogen and lipid peroxides which may contribute to prostate cancer development. GPX1 is one of only a small number of proteins known in higher vertebrates to contain selenocysteine, which occurs at the active site of glutathione peroxidase and is coded by the nonsense (stop) codon TGA. Furthermore, the GPX1 protein is characterized in a polyalanine sequence polymorphism in the N-terminal region, which includes 3 alleles with 5, 6 or 7 alanine (ALA) repeats in this sequence. The allele with 5 ALA repeats is significantly linked to breast cancer risk.

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.

EMC2 is an element of the ER membrane protein complex. EMC2 is a member of the EMC2 family and holds 3 TPR repeats.

Calcium-activated nucleotidase 1 (CANT1) is a member of the apyrase family. The CANT1 protein is calcium-dependent nucleotidase with a preference for UDP. The order of activity with different substrates is as follows: UDP > GDP > UTP > GTP. Moreover, CANT1 has a very low activity towards ADP and an even lower activity towards ATP. As well as it doesn’t hydrolyze AMP and GMP. CANT1’s specific function is yet unknown, nevertheless its substrates are involved in several key signaling functions, including Ca2+ release, through activation of pyrimidinergic signaling. Mutations in the CANT1 gene are linked with Desbuquois dysplasia with hand anomalies.

Hydroxyacid Oxidase 1 (HAO1) is a part of the superfamily of the alpha hydroxy acid oxidases (HAO) enzymes. HAO1 catalyses the FMN mediated oxidation of glycolate to glyoxylate and glyoxylate to oxalate by reducing oxygen to hydrogen peroxide. HAO1 is expressed mainly in the liver and pancreas and is most active on twocarbon substrates such as glycolate. HAO1 isthe main cause of hyperoxaluria, a disorder in which large deposits of calcium oxalate form kidney stones.

Lysophosphatidylcholine acyltransferase 1 (LPCAT1) is a part of the 1-acyl-sn-glycerol-3-phosphate acyltransferase family. LPCAT1 is a key enzyme for remodeling phospholipids, including phosphatidylcholine. LPCAT1 possesses both acyltransferase and acetyltransferase activities and also mediates the conversion of 1-acyl-sn-glycero-3-phosphocholine (LPC) into phosphatidylcholine (PC). LPCAT1 presents a clear preference for saturated fatty acyl-CoAs, and 1-myristoyl or 1-palmitoyl LPC as acyl donors and acceptors, respectively. LPCAT1 synthesizes phosphatidylcholine in pulmonary surfactant and therefore playing an important role in respiratory physiology.

Placental Lactogen is a polypeptide hormone that is produced by the Syncytiotrophoblasts of the Placenta, also known as chorionic somatomammotropin. It has both GH and Prolactin activities on growth, lactation, and luteal steroid production. In women, placental lactogen secretion begins soon after implantation and increases to 1 g or more a day in late pregnancy. Placental lactogen is also an ins. antagonist.
Placental Lactogen Bovine is also capable of activating human and other heterologous GH receptors but not ruminat GH receptors.

SKP1 is a F-box enzyme which functions as a substrate recognition component of the SCF ubiquitin ligase complex which controls the ubiquitination of proteins involved in cell cycle progression, signal transduction and transcription. SKP1 binds to proteins containing an F-box motif, such as cyclin F, S-phase kinase-associated protein 2, and other regulatory proteins involved in ubiquitin dependent proteolysis. SKP1 takes part in the control of beta-catenin levels and the activity of beta-catenin dependent TCF transcription factors. SKP1 serves as an adapter that links the F-box protein to CUL1 in the SCF complex.

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.

ALDH2 is part of the aldehyde dehydrogenase family of proteins which catalyze the chemical transformation from acetaldehyde to acetic acid. ALDH2 is the second enzyme of the major oxidative pathway of alcohol metabolism. ALDH2 has 2 major liver isoforms: cytosolic and mitochondrial, which differ by their electrophoretic mobilities, kinetic properties, and subcellular localizations. Nearly all Caucasians have 2 major isozymes, whereas roughly 50% of Orientals have only the cytosolic isozyme, omitting the mitochondrial isozyme. The extremely higher rate of acute alcohol intoxication with Orientals compared to Caucasians is due to the fact of the absence of mitochondrial isozyme. ALDH2 has a low Km for acetaldehydes, and is localized in mitochondrial matrix.

NDUFV3 is one of no less than 41 subunits which form the NADH-ubiquinone oxidoreductase complex that is involved in the mitochondrial respiratory chain and assists in catalyzing the rotenone-sensitive oxidation of NADH and the reduction of ubiquinone. NDUFV3 is 1 of 3 proteins found in the flavoprotein fraction of the complex but it exact function is unknown. Two transcript variants encoding altered isoforms are known for this gene.

DTD2 is e member of the DTD family. DTD2 protein hydrolyzes D-tyrosyl-tRNA(Tyr) into D-tyrosine and free tRNA(Tyr) as a defense mechanism against a harmful effect of D-tyrosine.

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.

Gltathione S-transferase PI 2, also known as GSTP2 is multifunctional enzyme which is involved in the protection of cellular components against anti-cancer drugs or peroxidative stress. Furthermore, down regulation of GSTP2 induces an increase of oxidative damage in the pyramidal cells of the CA1&CA3 regions as well as in the granular layer of the dentate gyrus, which at the end leads to structural and functional damage.

ErbB3, also called Her3 (human epidermal growth factor receptor 3), is a type I membrane glycoprotein that is a member of the ErbB family of tyrosine kinase receptors. ErbB family members serve as receptors for the epidermal growth factor (EGF) family of growth factors. Among ErbB family members, ErbB3 is unique in that it contains a defective kinase domain. ErbB3 is expressed in keratinocytes, melanocytes, skeletal muscle cells, embryonic myoblasts and Schwann cells. Monomeric ErbB3 serves as a low affinity receptor for the heregulins (HRG). ErbB3 can induce specific antibody production in vivo, hence to inhibit tumor cell growth. ErbB-3 can be used to treat early, medium and advanced or post-operative breast cancer with over-expression of ErbB2. According to its mechanism of action, ErbB3 is classified as a therapeutic for cancer.

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.

AKR7A3, takes part in the detoxification of aldehydes and ketones. AKR7A3 reduces the dialdehyde protein-binding form of aflatoxin B1 (AFB1) to the non-binding AFB1 dialcohol. AKR7A3 participates in protection of liver against the toxic and carcinogenic effects of AFB1, a potent hepatocarcinogen.

SEPSECS catalyzes the last step of sec synthesis by converting O-phosphoseryl-tRNA(sec) to selenocysteinyl-tRNA(sec) using selenophosphate as the selenium donor. Furthermore, SEPSECS protein is considered a specific marker of autoimmune hepatitis.