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SCO Cytochrome Oxidase Deficient Homolog 1, also known as SCO1 is a member of the SCO1/2 family. Mammalian cytochrome c oxidase (COX) catalyzes the transfer of reducing equivalents from cytochrome c to molecular oxygen and pumps protons across the inner mitochondrial membrane. Furthermore, in yeast, two related COX assembly genes, SCO1 & SCO2 which are synthesis of cytochrome c oxidase, enable subunits 1 as well as 2 to be incorporated into the holoprotein. This gene is the human homolog to the yeast SCO1 gene. Among the diseases associated with SCO1 are hepatic failure, early-onset, neurologic disorder due to cytochrome c oxidase deficiency and fatal infantile cytochrome c oxidase deficiency.

TRIM21 is a member of the tripartite motif (TRIM) family. The TRIM motif includes three zinc-binding domains, a RING, a B-box type 1 and a B-box type 2, and a coiled-coil region. The 52 kDa Ro protein is part of the RoSSA ribonucleoprotein, which includes a single polypeptide and one of four small RNA molecules. The RoSSA particle localizes to both the cytoplasm and the nucleus. Ro/SSA interacts with autoantigens in patients with Sjogren syndrome and systemic lupus erythematosus. Ribonucleoprotein particle is composed of a single polypeptide and one of four small RNA molecules. The RoSSA is present in all mammalian cells studied but has no known function. At least 2 isoforms are present in nucleated and red blood cells, and tissue specific differences in Ro/SSA proteins were identified.

CREB/ATF BZIP Transcription Factor, also known as CREBZF activates transcription strongly once bound to HCFC1. CREBZF suppresses the expression of HSV proteins in cells infected with the virus in a HCFC1-dependent manner. CREBZF suppresses the HCFC1-dependent transcriptional activation through CREB3 and reduces the quantity of CREB3 in the cell. In addition, CREBZF is capable to down-regulate expression of a few cellular genes in CREBZF-expressing cells.

Myelin Protein Zero-Like 1 (MPZL1) is a cell surface receptor, which is involved in signal transduction processes. MPZL1 recruits PTPN11/SHP-2 to the cell membrane and is a putative substrate of PTPN11/SHP-2. MPZL1 is a main receptor for concanavalin-A (ConA) and it is involved in cellular signaling induced by ConA, which most likely includes Src family tyrosine-protein kinases. MPZL1 Isoform 3 appears to have a dominant negative role by blocking tyrosine phosphorylation of MPZL1 induced by ConA. Isoform 1, but not isoform 2 and isoform 3, might be involved in regulation of integrin-mediated cell motility.

NFKB inhibitor interacting Ras-like 2 (NKIRAS2) is an inhibitor of the transcription factor NF-kappaB. NKIRAS2 is similar to the Ras-like small GTPases which associate with IkappaB. The Ras-like proteins- NKIRAS1 and NKIRAS2, interact with the PEST domains of I?B? and I?B? and reduce their rate of degradation. NKIRAS2 is an atypical Ras-like protein which functions as a potent regulator of NF-kappa-B activity by preventing the degradation of NF-kappa-B inhibitor beta (NFKBIB) by most signals, explaining why NFKBIB is more impervious to degradation.

Streptavidin is a tetrameric protein secreted by Streptomyces avidinii which binds firmly to biotin. Streptavidin is wilyde used in molecular biology through its unique high affinity for the vitamin biotin. The dissociation constant (Kd) of the biotin-streptavidin complex is about ~10-15 mol/L. The strong affinity recognition of biotin and biotinylated molecules has made streptavidin one of the most important components in diagnostics and laboratory kits. The streptavidin/biotin system has one of the biggest free energies of association of yet observed for noncovalent binding of a protein and small ligand in aqueous solution (K_assoc = 10**14). The complexes are also extremely stable over a wide range of temperature and pH.

Insulin-like growth factor-binding protein 4 (IGFBP-4) belongs to the insulin-like growth factor binding protein (IGFBP) family. IGFBP4 includes an IGFBP domain and a thyroglobulin type-I domain. IGFBP4 binds both insulin-like growth factors (IGFs) I and II. IGFBP-4 circulates in the plasma in both glycosylated and non-glycosylated forms. IGFBPs can either inhibit or enhance the biological activities of IGF, or act in an IGF independent manner. IGFBP-4 is exceptional since it consistently inhibits several cancer cells in vivo and in vitro, suggesting that it may function as an apoptotic factor. IGFBP4 is produced by all colon cancer cells. Binding of IGFBP-4 prolongs the half-life of the IGFs and changes their interaction with cell surface receptors.

HAND1 is a member of the basic helix-loop-helix family of transcription factors. HAND1 is one of two HAND proteins, two closely related family members that are irregularly expressed in the emerging ventricular chambers and have a key part in cardiac morphogenesis. Operating in a complementary manner, they work in the development of the right ventricle and aortic arch arteries, implicating them as mediators of congenital heart disease. Furthermore, HAND1 is obligatory for early trophoblast differentiation.

PSMB1 is part of the proteasome B-type family, also identified as the T1B family, that is a 20S core beta subunit. PSMB1 is tightly linked to the TBP (TATA-binding protein) gene in human and in mouse, and is transcribed in the opposite orientation in both species.The main function of PSMB1 is its degradation activity of unnecessary or damaged proteins by proteolysis. PSMB1 is a multicatalytic proteinase complex which is characterized by its ability to cleave peptides with arg, phe, tyr, leu, and glu adjacent to the leaving group at neutral or slightly basic ph. the proteasome has an atp-dependent proteolytic activity.

The bone morphogenetic protein (BMP) receptors are a family of transmembrane serine/threonine kinases that include the type I receptors BMPR1A and BMPR1B and the type II receptor BMPR2. These receptors are also closely related to the receptors, ACVR1 and ACVR2. The ligands of these receptors are members of the TGF-beta superfamily. TGF-betas transduce their signals through the formation of heteromeric complexes with 2 different types of serine (threonine) kinase receptors: type I receptors of about 50-55 kD and type II receptors of about 70-80 kD. Type II receptors bind ligands in the absence of type I receptors, but they require their respective type I receptors for signaling, whereas type I receptors require their respective type II receptors for ligand binding.

Epidermal growth factor has a profound effect on the differentiation of specific cells in vivo and is a potent mitogenic factor for a variety of cultured cells of both ectodermal and mesodermal origin. The EGF precursor is believed to exist as a membrane-bound molecule which is proteolytically cleaved to generate the 53-amino acid peptide hormone that stimulates cells to divide. EGF stimulates the growth of various epidermal and epithelial tissues in vivo and in vitro and of some fibroblasts in cell culture.

Acyl-CoA binding domain containing 6, also known as ACBD6 contains 1 ACB (acyl-CoA-binding) domain and 2 ANK repeats. ACBD6 binds long-chain acyl-coenzyme A molecules with a strong preference for unsaturated C18:1 CoA, lower affinity for unsaturated C20:4-CoA, and extremely weak affinity for saturated C16:0-CoA. Moreover ACBD6 does not bind fatty acids. ACBD6 has been detected in placenta, umbilical cord blood, CD34-positive hematopoietic progenitor cells and bone marrow. Endotheliitis has been associated with ACBD6.

Mitochondrial ribosomes (mitoribosomes) consist of a small 28S subunit and a large 39S subunit. Mitochondrial Ribosomal Protein S28, also known as MRPS28, is a protein coding gene which encodes a 28S subunit protein which is known as mitochondrial ribosomal protein S35.

Polymeric immunoglobulin receptor (PIGR) is responsible for transcytosis of soluble dimeric IgAs and immune. PIGR binds polymeric IgA and IgM at the basolateral surface of epithelial cells, then the complex is transported across the cell to be secreted at the apical surface.cytokines, hormones, and pathogenic stimuliregulate PIGR expression. The expression of PIGR is critically regulated by the pro-inflammatory cytokines, such as IL-1, IL-4, TNF-α, and IFN-γ.

Latexin enzyme is a carboxypeptidase A inhibitor that is highly expressed in the heart, prostate, ovary, kidney, pancrease, brain and colon. Latexin has no noticeable sequence resemblance with plant and parasite inhibitors, however it is related to a human putative tumor suppressor protein, TIG1. Latexin is down-regulated in the presenilin-1-deficient mouse brain, thus putatively playing a role in Alzheimer's disease.

GLC8 is a regulatory subunit of protein phosphatase 1 (Glc7p). GLC8 plays a role in glycogen metabolism and chromosome segregation, and regulates Glc7p activity through conformational alteration; ortholog of the mammalian protein phosphatase inhibitor 2. Under regular conditions, GLC8 triggers GLC7, but when GLC8 is over epxressed, it inhibits Glc7p function. GLC8 is activated upon phosphoylation by Pho85p complexed with four cyclins (Pcl6p, Pcl7p, Pcl8p, or Pcl10p).

ZNF346 is a nucleolar, zinc finger protein which specially binds to double-stranded RNA or RNA/DNA fusions, instead of DNA alone. Zinc finger domains vital for dsRNA binding and essential for its nucleolar localization. ZNF346 takes part in cell growth and survival.

Ro 60 kDa autoantigen is an RNA-binding protein that binds to several small cytoplasmic RNA molecules known as Y RNAs. SSA2 may stabilize these RNAs from degradation. Sera taken from patients with Systemic Lupus Erythematosus (SLE) often contains antibodies that react with the normal cellular SSA2 protein as if this antigen was foreign.

VCAM1 is a member of the Ig superfamily. It is a cell surface sialoglycoprotein expressed by cytokine activated endothelium. VCAM-1 contains 6 or 7 immunoglobulin domains, and is expressed on both large and small vessels only after the endothelial cells are stimulated by cytokines. The protein has a number of functions including the regulation of leukocyte migration, leukocyte endothelial cell adhesion and signal transduction and may play a role in a number of inflammatory diseases (artherosclerosis and rheumatoid arthritis).

Recombinant Human X-Ray Repair Cross Complementing Protein 3, also referred to XRCC3, is a member of RecA family and RAD51 subfamily. The protein takes partin homologous recombination to maintain chromosome stability and repair DNA damage. XRCC3functionally complements Chinese hamster irs1SF, a repair-deficient mutant that shows hypersensitivity to a number of different DNA-damaging agents & chromosomally unstable.

RDBP is a putative RNA binding protein. RDBP protein is one of the five components of the multisubunit NELF complex which collaborates with DSIF to repress RNA polymerase II elongation. Control of transcription elongation needs a complex interaction between positive transcription elongation factor b and negative transcription elongation factors, DSIF and NELF. DSIF and NELF, act as negative transcription elongation factors by increasing the time the polymerase spends at pause sites. RDBP has a functional RNA-binding domain, whose mutations impair transcription repression without affecting known protein-protein interactions.

VAMP4 belongs to the synaptobrevin family who are involved in docking and/or fusion of vesicles with cell membrane. VAMP4 is enriched in the trans-Golgi network and may be a factor in the trans-Golgi network-to-endosome transport. VAMP4 is involved in the pathway which functions to eliminate an inhibitor (most likely synaptotagmin-4) of calcium-triggered exocytosis during the maturation of secretory granules. Synaptobrevins, syntaxins, and SNAP25 are the chief components of a protein complex involved in the docking and/or fusion of synaptic vesicles with the presynaptic membrane.

Recombinant Hirudin is a potent thrombin inhibitor originally derived from the medicinal leech. Hirudin acts directly on thrombin rather than through other clotting factors. The mechanism of Hirudin-thrombin appears to be unique. The conversion of fibrinogen into fibrin by the serine protease enzyme thrombin is a major event in the final stages of blood coagulation. In the final stages of coagulation prothrombinase converts prothrombin into thrombin. Fibrin is subsequently cross linked by factor XIII to form a blood clot. The primary inhibitor of thrombin in normal blood circulation is antithrombin III. The anticoagulatant activity of hirudin is derived from its ability to inhibit the pro-coagulant activity of thrombin (similar to antithrombin III activity). Hirudin is the strongest natural inhibitor of thrombin. Hirudin binds to and inhibits only the activity of thrombin forms with a specific activity on fibrinogen contrasting to antithrombin III activity. Therefore, hirudin has a thrombolytic activity since it prevents or dissolves the formation of clots and thrombi. Hirudin also has therapeutic significance in blood coagulation disorders, in the treatment of skin hematomas and of superficial varicose veins. Hirudin does not hinder with the biological activity of other serum proteins and can also act on complexed thrombin, thus having an advantage over more common anticoagulants and thrombolytics. It is complicated to extract large quantities of hirudin from natural sources; therefore a method for producing and purifying hirudin using recombinant biotechnology has been developed.