Search results

Thioredoxins are small disulphide-containing redox proteins (within the conserved Cys-Gly-Pro-Cys active site) that have been found in all the kingdoms of living organisms. Thioredoxin contains a single disulfide active site and serves as a general protein disulphide oxidoreductase. Thioredoxins are involved in the first unique step in DNA synthesis. It interacts with a broad range of proteins by a redox mechanism based on reversible oxidation of two cysteine thiol groups to a disulphide, accompanied by the transfer of two electrons and two protons. The net result is the covalent interconversion of a disulphide and a dithiol. It has been suggested that thioredoxin may catalyze the formation of correct disulfides during protein folding because of its ability to act as an efficient oxidoreductant. Trx also provides control over a number of transcription factors affecting cell proliferation and death through a mechanism referred to as redox regulation.

Ras-related protein Rab-2A (RAB2A)is a member of the small GTPase superfamily. RAB protein family members are nontransforming monomeric GTP-binding proteins of the Ras superfamily, which contain four highly conserved regions involved in GTP binding and hydrolysis. In addition, RAB proteins are a fundamental part of endocytic pathways. RAB2A and RAB2B are essential for protein transport from the ER to the Golgi; RAB2A is lipid-anchored to the ER-Golgi intermediate compartment membrane whereas RAB2B is lipid anchored to the cytoplasmic side of the cell membrane. RAB2A also interacts with GOLGA2.

RARRES2 is a secreted chemotactic protein that initiates chemotaxis through the ChemR23 G protein-coupled seven-transmembrane domain ligand. RARRES2 acts as an adipokine, and is truncated on both termini from the proprotein. RARRES2 is structurally related to the cathelicidin precursors, cystatin C and kininogens. RARRES2 promotes calcium mobilization and chemotaxis of immature dendritic cells and macrophages. RARRES2 is secreted as a precursor of little biological activity, which requires proteolytic cleavage of its COOH-terminal domain to be exchangeed into a potent and highly specific agonist of ChemR23. RARRES2 signals via its receptor, ChemR23 (CMKLR1), as a positive regulator of adipocyte differentiation and metabolic function. The Chemerin receptor acts as a coreceptor for SIV and some primary HIV-1 strains.

NT3 a member of the neurotrophin family, that controls survival and differentiation of mammalian neurons. This protein is closely related to both nerve growth factor and brain-derived neurotrophic factor. It may be involved in the maintenance of the adult nervous system, and may affect development of neurons in the embryo when it is expressed in human placenta. NTF3-deficient mice generated by gene targeting display severe movement defects of the limbs. The mature peptide of this protein is identical in all mammals examined including human, pig, rat and mouse.

Ribosomes, the organelles which catalyze protein synthesis, contain a small 40S subunit and a large 60S subunit. Together these subunits are composed of 4 RNA species and nearly 80 structurally different proteins. RPL35A is a component of the 60S subunit of the ribosomal protein and a member of the L35AE family of ribosomal proteins. RPL35A is situated in the cytoplasm. The rat protein is known to bind to both initiator and elongator tRNAs, therefore, it is located at the P site, or P and A sites, of the ribosome. Though RPL35A was initially mapped to chromosome 18, it has been proven that it is located at 3q29-qter. Transcript variants utilizing alternative transcription initiation sites and alternative polyA signals exist. As is typical for genes encoding ribosomal proteins, there are several processed pseudogenes of this gene spread all over the genome.

Alpha and Beta Defensins are cationic peptides with antimicrobial activity against Gram-negative and Gram-positive bacteria, fungi and enveloped viruses. These 2-6kDa proteins have vital roles in innate immune system. Mammalian Defensins are classified into alpha, beta and theta categories, based on their size and pattern of disulfide bonding. Beta-Defensins contain a six-cysteine motif which forms 3 intra-molecular disulfide bonds. Since beta-defensins are cationic peptides, they can therefore interact with the membrane of invading microbes, which are negative due to lipopolysaccharides (LPS) and lipoteichoic acid (LTA) found in the cell membrane. In addition, they can affect the stability of the membrane.

ERCC1 polypeptide is essential for nucleotide excision repair (NER) of damaged DNA and is homologous to Saccharomyces cerevisiae RAD10, which takes part in repair and mitotic intra-chromosomal recombination. NER mechanism includes dual incisions on both sides of the damage catalyzed by two nucleases. In mammalian cells XPG cleaves 3' of the DNA lesion while the ERCC1-XPF complex makes the 5' incision.

TNFR2 belongs to the TNF-receptor superfamily. TNFR2 is receptor with high affinity for TNFSF2/TNF-alpha and approximately 5-fold lower affinity for homotrimeric TNFSF1/lymphotoxin-alpha. TNFR2 mediates the majority of the metabolic effects of TNF-alpha. In addition, knockout studies in mice propose a role for TNFR2 in protecting neurons from apoptosis by stimulating antioxidative pathways. TNFR2 expression might have a significant role in the angiogenesis, tumor cell proliferation and metastasis of Invasive micropapillary carcinoma of the breast.
There are 2 types of soluble TNF receptors: sTNFR-I and sTNFR-II, which act to neutralize the biological activities of TNF alpha and TNF beta. The levels of these soluble receptors seem to increase as a result of shedding of the extracellular domains of the membrane bound receptors. High levels of soluble TNF receptors are found in the amniotic fluid of pregnant women. TNFR2 and TNFR1 form a heterocomplex which mediates the recruitment of 2 anti-apoptotic proteins, c-IAP1 and c-IAP2, which possess E3 ubiquitin ligase activity. IAPs’ function in TNF-receptor signaling is unknown; nevertheless, c-IAP1 is believed to potentiate TNF-induced apoptosis by the ubiquitination and degradation of TNF-receptor-associated factor 2, which mediates anti-apoptotic signals. Oxidative stress promotes TNFR1 and TNFR2 self-interaction, ligand-independent and enhanced ligand-dependent TNF signaling. TNF-a, TNFR1 and TNFR2 have roles in cellular differentiation. TNFR1 and TNFR2 function in cell type-specific renal injury.

CD30 Ligand (TNFSF8) is a cytokine which is a member of the tumor necrosis factor (TNF) ligand family. The TNFSF8 cytokine is a ligand for TNFRSF8/CD30, which is a cell surface antigen and a marker for Hodgkin lymphoma and related hematologic malignancies. The employment of the TNFSF8 cytokine expressed on B cell surface has an inhibitory role in modulating Ig class switch. TNFSF8 enhances cell proliferation of some lymphoma cell lines, while inducing cell death and reducing cell proliferation of other lymphoma cell lines. The pleiotropic biological activities of the TNFSF8 cytokine on different CD30+ lymphoma cell lines has a pathophysiologic role in Hodgkin's and some non-Hodgkin's lymphomas.

G/U mismatch-specific DNA glycosylase (mug) is a part of the TDG/mug DNA glycosylase family. Mug is necessary for DNA damage lesion repair in stationary-phase cells. Mug protein removes three N4-ethenocytosine and takes away s the uracil base from mismatches in the order of U:G>U:A. The enzyme Uracil-N-Glycosylase removes uracil from the DNA leaving an AP position. Mug is also able to hydrolyzing the carbon-nitrogen bond among the sugar-phosphate backbone of the DNA and the mispaired base. The complementary strand guanine plays a role in substrate recognition.

DBR1 is an RNA lariat debranching enzyme which hydrolyzes 2'-5' prime branched phosphodiester bonds. The encoded protein specifically targets the bonds at the branch point of eliminated lariat intron RNA, transforming them to linear molecules which are then degraded. Additionally, DBR1 takes part in retroviral replication.

BAG3 Inhibits the chaperone activity of HSP70/HSC70 by promoting substrate release. BAG3 has anti-apoptotic activity. BAG proteins participate with Hip for their binding to Hsc70/Hsp70 ATPase domain and encourage substrate release. BAG proteins have about 45 amino acid BAG domain close to the C terminus however they differ noticeably in their N-terminal regions. BAG3 includes a WW domain in the N-terminal region and a BAG domain in the C-terminal region. The BAG domains of BAG1, BAG2, and BAG3 interact particularly with the Hsc70 ATPase domain in vitro and in mammalian cells. They bind with high affinity to the ATPase domain of Hsc70 and inhibit its chaperone activity in a Hip-repressible manner. BAG3 plays a role as a protein-refolding cochaperone of the bcl2 binding protein BAG family and as upregulated in response to persistent stress of cellular calcium balance dysregulation. BAG3 has been shown to diminish stress-induced apoptosis.

MAPT is a neuronal microtubule associated protein localized mostly on axons.
MAPT promotes tubulin polymerisation and stabilizes microtubules, however it also serves to connect certain signalling pathways to the cytoskeleton. MAPT, in its hyperphosphorylated form, is the main part of paired helical filaments (PHF) and neurofibrillary lesions in Alzheimer''s disease (AD) brain.

TNFRSF6B is a member of the Tumor necrosis factor receptor superfamily. TNFRSF6B performs as a decoy receptor which races against death receptors for ligand binding. TNFRSF6B has a regulatory role in suppressing FasL- and LIGHT-mediated cell death and T cell activation in addition to inducing angiogenesis via neutralization of TL1A.

CDC34 is important in the control of cell cycle and DNA replication. Cdc34 in association with different E3 complexes, including SCF, has been shown to target many different substrates for ubiquitination and degradation during cell division, signal transduction, and development. Cdc34 substrates that have been characterized include I?B, B-Myb, Wee1, MyoD, ICERII?, ATF5, p27Xic1, and p27Kip1. Additionally, substrates such as ?-catenin, p21Cip1, E2F, cyclin E, and cyclin D are putative substrates of Cdc34 by virtue of their SCF requirement for proteolysis. Cdc34 has been demonstrated to self-associate through a domain in the C-terminus, and is phosphorylated and ubiquitinylated in vivo. This protein is useful for in vitro ubiquitinylation reactions.

DNAJC19 is part of a complex involved in the ATP-dependent transport of transit peptide-containing proteins from the inner cell membrane to the mitochondrial matrix. DNAJC19 is a single-pass membrane protein which contains a J domain and is localized to the inner membrane of the mitochondrion. Expressed ubiquitously, DNAJC19 acts as a component of the mitochondrial DNAJC19 complex that is responsible for the ATP-dependent translocation of select proteins from the inner mitochondrial membrane to the mitochondrial matrix. Defects in the DNAJC19 gene are the cause of 3-methylglutaconic aciduria type 5 (MGA5), otherwise known as dilated cardiomyopathy with ataxia (DCMA).

Transcriptional adapter 3 (TATD3) is a subunit of 2 histone acetyltransferase complexes, which functions as a component of the PCAF complex. TATD3 is a transcriptional activator adaptor that is also associates with the tumor suppressor protein p53 and is essential for full activity of p53 and p53-mediated apoptosis.

TNF-b is a potent multifunctional cytokine produced mainly by activated T and B lymphocytes. The protein has been shown to have a specific potent cytotoxic activity on tumor cells and a variety of other target cells as well as being a mediator of inflammation and immune function.

HPRT1 has a main part in the generation of purine nucleotides through the purine salvage pathway. HPRT1 primarily functions to salvage purines from degraded DNA to renewed purine synthesis. Therefore, it performs as a catalyst in the reaction between guanine and phosphoribosyl pyrophosphate to form GMP.

TTC32 contains 3 TPR repeats. The tetratricopeptide repeat (TPR) is a structural motif. TPR is observed in organized 3–16 motifs, which form scaffolds to mediate protein–protein interactions and frequently the assembly of multiprotein complexes. TPR-containing proteins include the anaphase-promoting complex subunits cdc16, cdc23 and cdc27, the NADPH oxidase subunit p67-phox, hsp90-binding immunophilins, transcription factors, the major receptor for peroxisomal matrix protein import PEX5, the PKR protein kinase inhibitor and mitochondrial import proteins.

TXNL1 is a cytoplasmic protein which takes part in endocytotic signaling pathways and acts as a redox sensor. TXNL1 is universally expressed in the body and its goal is to couple oxidative stress to endocytosis, thereby regulating the GDI. Moreover, overexpression of TXNL1 inhibits cell proliferation by predisposing the cell to G0/G1 arrest, signifying that TXNL1 also functions as a transcriptional repressor.

Peptidyl-tRNA hydrolase 2 (PTRH2) is a mitochondrial protein. PTRH2 is released during apoptosis from the mitochondria to the cytoplasm. When in the cytoplasm, PTRH2 regulates the function of 2 transcriptional regulators, TLE5 and TLE1, thus promoting caspase-independent cell death. Natural substrates for PTRH2 may be petidyl-tRNAs which drop off the ribosome during protein synthesis.