Search results

TXNRD1 belongs to the selenium-containing pyridine nucleotide-disulphide oxidoreductase family, which has a conserved catalytic site of Cys-Val-Asn-Val-Gly-Cys. TXNRD1 decreases thioredoxins as well as other substrates, and participates in selenium metabolism and protection against oxidative stress. Inhibition of TXNRD1 activity serves as a potential treatment for cancer, AIDS and other autoimmune diseases as well as bacterial infections and parasitic diseases.

BRCC3 is a subunit of the BRCA1-BRCA2-containing complex (BRCC), which is an E3 ubiquitin ligase. BRCC3 is also thought to be involved in the cellular response to ionizing radiation and progression through the G2/M checkpoint.

Dihydrofolate reductase (DHFR) is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid, with NADPH as electron donor that can be converted to the kinds of tetrahydrofolate cofactors applied in 1-carbon transfer chemistry. DHFR converts dihydrofolate into tetrahydrofolate, which is a methyl group shuttle required for the de novo synthesis of purines, thymidylic acid, and specific amino acids. Even though the functional DHFR gene is mapped to chromosome 5, numerous intronless processed pseudogenes or dihydrofolate reductase-like genes are identified on separate chromosomes. DHFR deficiency is associated with megaloblastic anemia. DHFR knockdown plays a role in the anticancer activity of 2-hydroxyoleic acid. DHFR gene insertion/deletion polymorphism is linked to variation in serum and red blood cell folate concentrations in women.

DsbA appears to be necessary for correct formulation of disulfide bonds in exported proteins in vivo. DsbA is useful as a standard in immunoblotting. This protein catalyses the reduction and exchange of disulfide bonds and the oxidation of free sulfhydryl groups in vitro. It is the strongest oxidant of the thioredoxin superfamily. This thio/disulfide oxidoreductase is required for efficient disulfide bond formation in the periplasm of E. coli.

Short/branched chain specific acyl-CoA dehydrogenase (ACADSB) belongs to the acyl-CoA dehydrogenase family of enzymes which catalyze the dehydrogenation of acyl-CoA derivatives in the metabolism of fatty acids or branch chained amino acids. ACADSB catalyzes the degradation of L-isoleucine while having the highest affinity for (s)-2-methylbutyryl-CoA, isobutyryl-CoA and 2-methylhexanoyl-CoA as substrates. ACADSB may use valproyl-CoA as substrate. ACADSB gene defects cause the short/branched-chain acyl-CoA dehydrogenase deficiency (SBCADD), which is an autosomal recessive disorder characterized by an increase of 2-methylbutyrylglycine and 2-methylbutyrylcarnitine in blood and urine.

UGDH is part of the UDP-glucose/GDP-mannose dehydrogenase family and is a widely expressed enzyme localized in the liver. UGDH transfers UDP-glucose to UDP-glucuronate and thus takes part in the biosynthesis of glycosaminoglycans such as hyaluronan, chondroitin sulfate, and heparan sulfate. These glycosylated products are ordinary molecules of the extracellular matrix and participate in signal transduction, cell migration, and cancer growth and metastasis.

MGMT is an enzyme that repairs O-6-methylguanine, a mutagenic DNA base damaged by endogenous and environmental alkylating agents and takes part in the cellular defense against the biological effects of O-6-methylguanine in DNA. MGMT repairs alkylated guanine in DNA by stoichiometrically transferring the alkyl group at the O-6 position to a cysteine residue in the enzyme. abnormal MGMT expression correlates with the prognosis in human solid cancers. MGMT decrease of expression is correlated with methylation. The human MGMT is a negative regulator of estrogen receptor-mediated transcription upon alkylation DNA damage. MGMT promoter hypermethylation plays an important role in the early steps of colorectal carcinogenesis. Abnormal promoter hypermethylation of MGMT gene is associated with oral squamous cell carcinomas.

PPCDC is a member of the HFCD (homo oligomeric flavin containing Cys decarboxylase) superfamily which takes a part in the biosynthesis of coenzyme A (CoA) from pantothenate (Vitamin B). The biosynthesis of CoA from pantothenate needs several steps: the phosphorylation of pantothenate, the conversion of 4’-hosphopantothenate to 4''-phosphopantetheine, the adenylation by phosphopantetheine adenylyltransferase to form dephospho-CoA and the phosphorylation by dephospho-CoA kinase to form CoA. PPCDC is a key player in this pathway. PPCDC converts 4''-phosphopantothenate into 4''-phosphopantetheine.

Glutathione reductase (GSR) belongs to the class-I pyridine nucleotide-disulfide oxidoreductase family. The GSR enzyme is a homodimeric flavoprotein and has a role in maintaining glutathione (GSH) in its reduced form by catalyzing the reduction of glutathione disulfide (GSSG): GSSG + NADPH + H+ ->2GSH + NADP+. In the majority of eukaryotic cells, GSR upholds the ratio of [GSH] / [GSSG], and partakes in quite a few critical functions such as the detoxification of reactive oxygen species as well as protein and DNA biosynthesis.

The conserved 76 amino acid protein ubiquitin (Ub) regulates a host of intracellular processes through its enzymatic conjugation to other cellular proteins.
Ubiquitination occurs through sequential steps catalyzed by activating (E1), conjugating (E2), and ligase (E3) enzymes. The final step results in the formation of an isopeptide bond between Ub’s C-terminal glycine residue (G76) and a lysine residue of the target protein, although N-terminal ubiquitination is also known.
Outcomes of this modification include destabilization of the conjugated protein, altered protein trafficking and functional modulation.
After targeting the protein for specific localizations, ubiquitin is released from the substrate by deubiquitinating enzymes.
A mutant ubiquitin, having a Gly to Ala substitution at the C-terminus (G76A ubiquitin) supported several downstream reactions of the proteolytic pathway but inhibits the deubiquitination process.
As consequence, the Ub derivative becomes irreversibly conjugated to protein, shifting the equilibrium between the bound and unbound form in the direction of conjugation, at the expense of the free form.

Sepiapterin Reductase is an aldo-keto reductase that catalyzes the NADPH-dependent reduction of pteridine derivatives and is essential in the biosynthesis of BH4. Mutations in Sepiapterin Reductase gene result in DOPA-responsive dystonia due to sepiaterin reductase deficiency defined by the presence of sustained involuntary muscle contractions, often leading to abnormal postures. Sepiapterin reductase is part of the short-chain dehydrogenase/reductase family which reduces exogenous carbonyl compounds as well as phenylpropanedione. Sepiapterin reductase is an important enzyme for the biosynthesis of tetrahydrobiopterin, an necessary cofactor for aromatic amino acid hydrolases together with tyrosine hydroxylase, the rate-limiting enzyme in dopamine synthesis.

PRDX2 is part of the peroxiredoxin family of antioxidant enzymes, which reduce hydrogen peroxide and alkyl hydroperoxides. PRDX2 takes part as an antioxidant protective role in cells, and contributes to the antiviral activity of CD8(+) T-cells. PRDX2 has proliferative effect in cancer development or progression.
If PRDX2 protection is insufficient against peroxidases, the DNA damage results in neurological disease such as Alzheimer's or DNA damage leading to cancer.

CDO1 (Cysteine dioxygenase) is a mammalian non-heme iron enzyme that initiates a number of significant metabolic pathways associated with pyruvate and several sulfurate compounds including sulfate, hypotaurine and taurine. CDO1 catalyzes the conversion of L-cysteine to cysteine sulfinic acid (cysteine sulfinate) by incorporation of dioxygen. CDO1 is a vital regulator of cellular cysteine concentrations and has an essential role in maintaining the hepatic concentration of intracellular free cysteine within a proper narrow range. CDO1 is able to alter intracellular cysteine levels and glutathione levels. CDO1 is highly expressed in the liver and placenta. On the other hand CDO1 has a low expression in heart, brain and pancreas. CDO1 can also be detected in hepatoblastoma HepG2 cells.

Cytochrome C Oxidase Subunit Va (COX5A) is a member of the cytochrome c oxidase subunit 5A family. COX (Cytochrome C Oxidase), which is the terminal component of the mitochondrial respiratory chain, catalyzes the electron transfer from reduced Cytochrome C to oxygen. The COX component is a heteromeric complex comprised of three catalytic subunits encoded by mitochondrial genes and multiple structural subunits encoded by nuclear genes. The mitochondrially-encoded subunits serve in electron transfer, and the nuclear-encoded subunits act in the regulation and assembly of the complex. COX5A is the heme A-containing chain of Cytochrome C Oxidase,which is the terminal oxidase in mitochondrial electron transport.

Disulfide Oxidoreductase or DsbA is a protein, found in the plasma. It is part of the thioredoxin protein family. The protein creates disulfide bonds in the target proteins by contributing disulfide bond from its Cys30-Pro31-His32-Cys33 active site to a couple of cysteine residues.

Ubiquitin is a highly conserved 76 amino acid protein expressed in all eukariotes. Ub is found either in free form or conjugated to proteins as monomer or as chain of ubiquitin molecules. The most well characterized consequence of polyubiquitination is substrate degradation, while mono-ubiquitinated proteins are not degraded. Ubiquitin attachment to protein substrate is a complex process involving a ubiquitin activating enzyme (E1), a ubiquitin conjugating enzyme (E2) and a ubiquitin protein ligase (E3). The first ubiquitin moiety is transferred to the e-NH2 group of a Lys residue of the protein substrate to generate an isopeptide bond. In successive reactions, a poly ubiquitin chain is synthesized by processive transfer of additional activated moieties to Lys48 of the previously conjugated ubiquitin molecule. Ubiquitin K48R prevents the formation of poly ubiquitin chains via Lys48 linkages with mono ubiquitin molecules, avoiding the degradation of protein substrates.

AKR1B1 is part of the aldo/keto reductase superfamily, which consists of more than 40 known enzymes and proteins. AKR1B1 catalyzes the reduction several aldehydes, including the aldehyde form of glucose, and thus involved in the development of diabetic complications by catalyzing the reduction of glucose to sorbitol. AKR1B1 catalyzes the NADPH-dependent reduction of a wide variety of carbonyl-containing compounds to their corresponding alcohols. Transgenic mice over expressing human aldose reductase show that AKR1B1 is a key player in ischemic injury and impairment of functional and metabolic recovery after ischemia. Aldose Reductase is an obligatory mediator of TNF-alpha signaling leading to an increase in the expression of adhesion molecules and increased binding of monocytes to the endothelium. AKR1B1 is a critical regulator of TNF-alpha-induced apoptotic signaling in endothelial cells.

L-lactate dehydrogenase (lldD) is present in a various organisms, including plants and animals. lldD is an oxidoreductase which catalyses the interconversion of pyruvate and lactate with concurrent interconversion of NADH and NAD+. Seeing that lldD can catalyze the oxidation of hydroxybutyrate, it is occasionally called Hydroxybutyrate Dehydrogenase (HBD).

Matrix metalloproteinases are a family of zinc and calcium-dependent endopeptidases that break down extracellular matrix proteins. The MMP9 is secreted as a 92kDa zymogen. Cleavage of ProMMP-9 results in the active enzyme, having a molecular weight of approximately 82kDa. MMP9 is composed of the following domains: a gelatin-binding domain consisting of three fibronectin type II units, a catalytic domain containing the zinc-binding site, a proline-rich type V collagen-homologous domain and a hemopexin-like domain. MMP9 is produced by the several cell types: monocytes, macrophages, neutrophils, keratinocytes, fibroblasts, osteoclasts and endothelial cells. MMP9 is involved in inflammatory responses, tissue remodeling, wound healing, tumor growth and metastasis. MMP9 may also play an important part in local proteolysis of the extracellular matrix and in leukocyte migration, as well as in bone osteoclastic resorption. MMP9 cleaves type IV and type V collagens into large C-terminal three quarter fragments and shorter N-terminal one quarter fragments. MMP9 can also degrade fibronectin but not laminin or Pz-peptide.
MMP9 defects may be a cause of susceptibility to intervertebral disc disease (IDD), also known as lumbar disk herniation (LDH).

TNF-related apoptosis-inducing ligand (TRAIL) is a ligand molecule which induces apoptosis. It is a type II transmembrane protein with homology to other members of the tumor necrosis factor family.
In humans, the gene that encodes for TRAIL is located at chromosome 3q26. TRAIL binds to the death receptors, DR4 and DR5. The process of apoptosis is caspase-8-dependent. This protein preferentially induces apoptosis in transformed and tumor cells, but does not appear to kill normal cells although it is expressed at a significant level in most normal tissues.

GPX7 is a member of the glutathione peroxidase family. Glutathione peroxidases (GPx) are a family of enzymes with peroxidase activity whose central biological role is to guard the organism from oxidative damage by reducing lipid hydroperoxides to their corresponding alcohols and to reduce free hydrogen peroxide to water.

Carcinoembryonic antigen (CEA) is a glycoprotein present in fetal digestive-tract tissues; it’s involved in cell adhesion. The production of CEA stops before birth. CEA is called tumor marker since its elevated levels are found in the serum from individuals with colorectal, gastric, pancreatic, lung and breast carcinomas and in heavy smokers.
There are also benign conditions that elevate CEA levels such as smoking, infection, inflammatory bowel disease, pancreatitis, cirrhosis of the liver, and some benign tumors (in the equivalent organs which have cancers with elevated CEA). Typically, higher levels of CEA are found in men, smokers, and older individuals.
The presence of CEA assists in screening, in evaluating recurrent or disseminated disease, and in determining the success of surgical removal of malignant tumors.
CEA levels can be used as indicators of treatment success. The normal values range from 0.0 to 2.5 ng/ml of serum (from blood), in non-smokers, a greater amount than that may be suggestive of cancer. Levels above 20 ng/ml before treatment are associated with cancer which has already metastasized. Benign conditions do not usually cause a CEA increase over 10 ng/ml.
The high levels of CEA should return to normal after successful therapy, however if during follow up there’s an elevation in CEA levels it indicates a recurrence of tumor.
Carcinoembryonic antigen family belongs to the immunoglobulin superfamily; it consists of 29 genes, 18 of which are normally expressed.

GCK is an enzyme that expedite the formation of glucose-6-phosphate for glucose by phosphorylation. Humans and other vertebrates have GCK in the cells of the pancreas and liver. In both organs, the enzyme has an important role in carbohydrate metabolism regulation by sensing sugar levels and acting according to the change in glucose levels, that can rise after a meal or fall during fasting. Mutations in the gene that codes for this enzyme can cause hypoglycemia or diabetes.

.

C-JUN is a gene which, in combination with c-Fos, forms the AP-1early response transcription factor. C-JUN is activated by the JNKpathway. C-JUN is the putative transforming gene of avian sarcoma virus 17. C-JUN is a protein which is highly similar to the viral protein, and which interacts directly with specific target DNA sequences to regulate gene expression. The C-JUN gene is intronless and is mapped to 1p32-p31, a chromosomal region involved in both translocations and deletions in human malignancies.