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Human Pin 1 is a peptidyl-prolyl cis/trans isomerase (PPIase) that interacts with NIMA and essential for cell cycle regulation Pin1 is nuclear PPIase containing a WW protein interaction domain, and is structurally and functionally related to Ess1/Ptf1, an essential protein in budding yeast. PPIase activity is necessary for Ess1/Pin1 function in yeast. Pin1 is thus an essential PPIase that regulates mitosis presumably by interacting with NIMA and attenuating its mitosis-promoting activity. Substrates of Pin1 include the mitotic regulators (Cdc25 phosphatase and NIMA, PLK I, Wee, and Myt1 kinases), several transcription factors like b-Catenin, c-Jun, and the tumor suppressor protein p53, and some specific proteins like the RNA Pol II, the cytoskeleton protein tau, and the G1/S protein Cyclin D1.

Leukocyte Cell Derived Chemotaxin 1 (214-333 a.a.), also known as LECT1, is a glycosylated transmembrane protein which is cleaved to form a mature, secreted protein. The mature protein encourages chondrocyte growth and inhibits angiogenesis. The mature protein takes part in endochondral bone development by permitting cartilaginous anlagen to be vascularized and replaced by bone. LECT1 is expressed in the avascular area of prehypertrophic cartilage and its expression reduces during vascular invasion and chondrocyte hypertrophy.

PPM1G is part of the PP2C family of Ser/Thr protein phosphatases which are known to be negative regulators of cell stress response pathways. PPM1G is accountable for the dephosphorylation of Pre-mRNA splicing factors, an important factor for the formation of functional spliceosome. PPM1G regulates cell cycle progression. PPM1G mediates histone dephosphorylation/exchange in response to DNA damage or checkpoint recovery in higher eukaryotes. The degradation of p21/WAF1 induced by PPM1G is mediated in a proteasome-dependent manner. Protein phosphatase 1G regulates assembly and function of the beta-catenin degradation complex.

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.

CBR1 is one of numerous monomeric, NADPH-dependent oxidoreductases having ubiquistly specificity for carbonyl compounds. CBR1 is broadly distributed in human tissues. CBR1 metabolizes toxic environmental quinones and pharmacological relevant substrates. CBR1 converts prostaglandin E2 to prostaglandin F2-alpha.

Proteasome Subunit Beta Type 8 (PSMB8) is a member of the peptidase T1B family. The proteasome is a multicatalytic proteinase complex with well-organized ring-shaped 20S core structure. Proteasomes are spread through eukaryotic cells at a high concentration. PSMB8 is mainly expressed in immature dendritic cells. vital function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides.PSMB8 is positioned in the class II region of the MHC (main histocompatibility complex). PSMB8 plays as a significant factor of INFG-induced sensitivity and in apoptosis by degradation of the apoptotic inhibitor MCL1.

Alanyl-tRNA synthetase is a member of the aminoacyl-tRNA synthetase family, key enzymes of protein biosynthesis which charge tRNA molecules with the respective amino acids. This 108 kDa protein is an autoantigen recognized by PL-12 antibodies which occur in a subset of patients with polymyositis and dermatomyositis. Preliminary data suggest that epitope spreading occurs in the autoimmune PL-12 response such that even antibodies to an isolated alanyl-tRNA molecule can develop.

Prothymosin alpha (PTMA) is a part of the pro/parathymosin family. PTMA mediates immune function by conferring resistance to some opportunistic infections.

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.

GADD45GIP1 is a nuclear protein which takes part in apoptosis control. GADD45GIP1 is expressed in several tissues, such as heart, thyroid, trachea, kidney, ovary, pancreas, testis and stomach and acts as a negative regulator of G1 to S phase cell cycle production by collaborating with GADD45 proteins to inhibit the activity of cyclin-dependent kinases.

FKBP4 is part of the immunophilin protein family, which takes part in immunoregulation and necessary cellular processes concerning protein folding and trafficking. FKBP4 is a cis-trans prolyl isomerase that connects to the immunosuppressants FK506 and rapamycin. FKBP4 has high structural and functional similarity to FKBP1A, though, FKBP4 does not have immunosuppressant activity when complexed with FK506. FKBP4 is known to connect with phytanoyl-CoA alpha-hydroxylase. FKBP4 associates with HSP90 & HSP70 thus takes part in the intracellular trafficking of hetero-oligomeric forms of the steroid hormone receptors. FKBP4 highly associates with adeno-associated virus type 2 vectors (AAV) resulting in a considerable increase in AAV-mediated transgene expression in human cell lines. FKBP4 is involved in the optimal use of AAV vectors in human gene therapy.

USE1 Belongs to the USE1 family, this protein is a vesicle transport protein. USE1 is a component of a SNAREcomplex consisting of STX18, USE1L, BNIP1/SEC20L and SEC22B. In addition USE1 interacts directly with STX18. SNARE maybe involved in targeting and fusion of Golgi-derived retrograde transport vesicles with the ER. Diseases associated with USE1 comprise dysentery and hemolytic-uremic syndrome. Among its related super-pathways are Nicotine Pathway (Dopaminergic Neuron) and Pharmacodynamics. GO annotations related to this gene include protein binding.

BCAT1 catalyzes the leading reaction in the catabolism of the indispensable branched chain amino acids isoleucine, leucine and valine.

RAB, Member RAS Oncogene Family-Like 5 (RABL5) belongs to the Ras superfamily of small GTP-binding proteins. The Ras-related superfamily of guanine nucleotide binding proteins includes the R-Ras, Rap, Ral/Rec and Rho/Rab subfamilies. Rab proteins have an essential role in endocytosis or in biosynthetic protein transport. The transporting process of newly synthesized proteins from the endoplasmic reticulum to various stacks of the Golgi complex and to secretory vesicles includes the movement of carrier vesicles and requires Rab protein function.

Protein Phosphatase 2C alpha is a member of the PP2C family of Ser/Thr protein phosphatases. PP2C family members are known to be negative regulators of cell stress response pathways. This phosphatase dephosphorylates, and negatively regulates the activities of, MAP kinases and MAP kinase kinases. It has been shown to inhibit the activation of p38 and JNK kinase cascades induced by environmental stresses. This phosphatase can also dephosphorylate cyclin-dependent kinases, and thus may be involved in cell cycle control. Overexpression of this phosphatase is reported to activate the expression of the tumor suppressor gene TP53/p53, which leads to G2/M cell cycle arrest and apoptosis. Three alternatively spliced transcript variants encoding two distinct isoforms have been described.
Protein phosphatase 2C(PP2C?) is a Mn2+- or Mg2+-dependent protein serine/threonine phosphatase that is essential for regulating cellular stress response in eukaryotes.

Bcl-2–associated X protein (Bax) belongs to the Bcl-2 protein family. Bax is a pro-apoptotic Bcl-2 protein containing BH1, BH2 and BH3 domains. Bax accelerates programmed cell death by binding to, and antagonizing the apoptosis repressor bcl2 or its adenovirus homolog e1b 19k protein. Bax induces the release of cytochrome c, activation of casp3, and thereby apoptosis. Bax is expressed in a wide variety of tissues, with highest levels in the testis and ovary. Tumor suppressor protein p53 upregulates the expression of BAX. Bax has been shown to be involved in p53-mediated apoptosis.

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.

Cytokeratin 8 belongs to the type B (basic) subfamily of high molecular weight keratins and exists in combination with keratin 18. Cytokeratin 8 is primarily found in the non-squamous epithelia and is present in majority of adenocarcinomas and ductal carcinomas. It is absent in squamous cell carcinomas. Hepatocellular carcinomas are defined by the use of antibodies that recognize only cytokeratin polypeptides 8 and 18.

Protein Tyrosine Phosphatase Type IVA Member 3 (PTP4A3) is a member of a small class of prenylated protein tyrosine phosphatases (PTPs) which remove phosphate modifications from tyrosine residues on proteins. PTP4A3 enhances cell proliferation, cell motility and invasive activity. PTP4A3 functions as a protein tyrosine phosphatase which stimulates progression from G1 into S phase during mitosis. PTP4A3 is mostly expressed in cardiomyocytes and skeletal muscle; it is also found in the pancreas.
PTP4A3 is always overexpressed in colon cancer metastasis. PTP4A3 is notably overexpressed in liver metastasis of colorectal cancer. High levels of PTP4A3 expression are linked to tumorigenesis and metastasis; therefore it is overexpressed in metastatic colorectal, ovarian, liver and skin cancers. PTP4A3 may be involved in the progression of cardiac hypertrophy by inhibiting intracellular calcium mobilization in response to angiotensin II. PTP4A3 is inhibited by sodium orthovanadate and peroxovanadium compounds.

A natural cytotoxicity receptor (NCR) NKp46 has been shown to represent a novel NK cell-specific molecule involved in human NK cell activation. The natural cytotoxicity receptors (NCRs) are a recently characterized family of Ig-like activation receptors that appear to be major triggering receptors in tumor cell recognition. The three known NCRs include NKp46 and NKp30, which are expressed on circulating NKcells, and NKp44, which is expressed only on activating NK cells. NKp46 has been implicated in NK cell-mediated lysis of several autologous tumor cells, pathogen-infected cell lines and mononuclear phagocytes infected with an intracellular bacterium. The Lysis of tumor cells by NK-cells involves recognition by NKp46 of heparan sulfate moieties of membrane heparan sulfate proteoglycans. Furthermore, NKp46 is a surface receptor involved in NK-cell cell death by apoptosis. NKp46 has two extracellular Ig-like domains followed by a ~40 residue stalk region, a type I transmembrane domain, and a short cytoplasmic tail. The extracellular Ig-like domain of NKp46 (22-255aa) is purified by FPLC gel-filtration chromatography, after refolding of the isolated inclusion bodies in a redox buffer. In addition, engagement of the antigen with the monoclonal antibody stimulates intracellular calcium levels and the synthesis of cytokines. CD59 is an NKp46 coreceptor (by physical association) together they activate cytotoxicity of human NK-cells, their engagement results in tyrosine phosphorylation of CD3-zeta chains associated with NKp46. Reduced cell surface expression of NKp46 and other NK-cell receptors is linked to the impaired NK-cell cytolytic function in viremic HIV-1 infection.

Suppressor of Cytokine Signaling 3, also known as SOCS3 belongs to the SOCS family; in addition SOCS3 is a member of the STAT-induced STAT inhibitor (SSI). The SSI family members are cytokine-inducible negative regulators of cytokine signaling. The expression of SOCS3 is induced by different cytokines, including IL6 and IL10. SOCS3 can bind to JAK2 kinase, and inhibit the activity of JAK2 kinase. Studies of the mouse counterpart of SOCS3 have shown the roles of SOCS3 in the negative regulation of fetal liver hematopoiesis, and placental development.

PSMB5 belongs to the proteasome B-type family that has a 20S core beta subunit in the proteasome. This catalytic subunit is not present in the immunoproteasome and is substituted by catalytic subunit 3i (proteasome beta 8 subunit). A fundamental function of a modified proteasome, the immunoproteasome, is the processing of class I MHC peptides. PSMB5 exhibits an ATP dependent proteolytic activity and is involved in an ATP/ubiquitin dependent non lysosomal proteolytic pathway.

CDC123 is a member of the CDC123 family. CDC123is required for S phase entry of the cell cycle. It is also broadly expressed in spleen,thymus, prostate, testis, ovary, small intestine, colon and leukocytes with the uppermost expression in testis.