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PPIases catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides and accelerate the folding of proteins. Cyclophilin-A is a cyclosporin binding-protein and may play a role in cyclosporin A-mediated immunosuppression. Cyclophilin-A can also interact with several HIV proteins, including p55 gag, Vpr, and capsid protein, and has been shown to be necessary for the formation of infectious HIV virions. Multiple pseudogenes that map to different chromosomes have been reported.

ERO1-like protein alpha (ERO1L) is an essential oxidoreductase, which oxidizes proteins and is necessary for the folding of immunoglobulins. ERO1L covalently binds with PDI (protein disulfide-isomerase) and jointly they generate disulfide bonds between proteins in the endoplasmic reticulum. ERO1L is stimulated by hypoxia, proposing that ERO1L is regulated through the HIF (hypoxia inducible transcrip-tion factor) pathway. At low levels ERO1L is ubiquitously expressed, however at high levels it is expressed in the upper digestive tract and esophagus. In addition, ERO1L is involved in the release of the unfolded cholera toxin from reduced P4HB/PDI in case of infection by V.cholerae, thus having a role in retrotranslocation of the toxin. Furthermore, ERO1L plays an important role in ER stress-induced, CHOP-dependent apoptosis by activating the inositol 1,4,5-trisphosphate receptor IP3R1.

SRGN is identified as a hematopoietic cell granule proteoglycan. Proteoglycans stored in the secretory granules of various hematopoietic cells also hold a protease-resistant peptide core, and is vital for neutralizing hydrolytic enzymes. SRGN is related to the macromolecular complex of granzymes and perforin that acts as a intermediary of granule-mediated apoptosis.

LAMTOR2 is a member of the GAMAD family. LAMTOR2 is highly conserved with a mouse protein linked with the cytoplasmic face of late endosomes and lysosomes. The mouse protein interacts with MAPK scaffold protein 1, which is a component of the mitogen-activated protein kinase pathway. LAMTOR2 gene mutation has been associated with a primary immunodeficiency syndrome in humans, proposing a role for this protein in endosomal biogenesis.

Mycobacterium antigen ESAT6 has been isolated from low molecular weight fractions of the shot-term-culture filtrate (ST-CF) and it can easily be detected in tuberculosis patients. The export of ESAT-6 which is a potent T-cell antigen, and related proteins requires a dedicated secretory apparatus that is encoded by a group of genes, several of which also code for proteins that are recognized strongly by T cells. The ESAT-6 systems can consequently be considered as immunogenicity islands and there is mounting evidence that the equivalent genes are subject to selective pressure imposed by the immune system of the host. This antigen includes many epitopes detectable in the serum of most patients with tuberculosis (more than 90%). By the attempts to obtain the vaccine on the basis of ESAT-6 it was demonstrated that the optimization of adjuvant is very important when using the combination of dioctadecylammonium bromide and monophosphoryllipide. ESAT-6 is very potential as diagnostic for differentiation between the mycobacterial infection and BCG vaccination. The main topic in ESAT-6 using is in antibody production and in test-systems for tuberculosis elaboration. Early secretory antigen 6 (ESAT6) and cell filtrate protein 10 (CFP10) are 2 antigens secreted as a complex by the replicating Mycobacterium tuberculosis complex (MTC).

Uromodulin is the most abundant protein in normal urine. Its secretion in urine follows proteolytic cleavage of the ectodomain of its glycosyl phosphatidylinosital-anchored counterpart that is situated on the luminal cell surface of the loop of Henle. Uromodulin plays a role as a constitutive inhibitor of calcium crystallization in renal fluids. Secretion of uromodulin in urine provides protection against urinary tract infections caused by uropathogenic bacteria. Defects in Uromodulin expression are associated with the autosomal dominant renal disorders medullary cystic kidney disease-2 (MCKD2) and familial juvenile hyperuricemic nephropathy (FJHN). These disorders are characterized by juvenile onset of hyperuricemia, gout, and progressive renal failure. While several transcript variants may exist for this gene, the full-length natures of only two have been described to date. UMOD is involved in regulating the circulating activity of cytokines as it binds to il-1, il-2 and tnf with high affinity.

Lipopolysaccharides (LPS) are a type of glycolipids on the outer cell wall of Gram-negative bacteria. Lipopolysaccharide binding protein (aka LBP) is a plasma protein which facilitates the diffusion of bacterial LPS (endotoxin). LBP is involved in the acute-phase immunologic response to gram-negative bacterial infections. In cooperation with bactericidal permeability-increasing protein (BPI), LBP binds LPS and interacts with the CD14 receptor, most likely playing a role in regulating LPS-dependent monocyte responses. LBP belongs to a family of structurally and functionally related proteins, including BPI, plasma cholesteryl ester transfer protein (CETP), and phospholipid transfer protein (PLTP). The LBP gene is found on chromosome 20, directly downstream of the BPI gene. LBP catalyzes the transfer of LPS monomers from LPS aggregates to HDL particles, to phospholipid bilayers, and to a binding site on soluble CD14 (sCD14). sCD14 is capable of speeding up the transfer by receiving an LPS monomer from an LPS aggregate, and then yielding it to an HDL particle, therefore acting as a soluble "shuttle" for an insoluble lipid.

Listeriolysin O (aka LLO) is a hemolysin produced by Listeria monocytogenes bacteria, the pathogen responsible for causing listeriosis. The toxin may be regarded as a virulence factor, since it is crucial for the virulence of L. monocytogenes. LLO is a single polypeptide protein encoded by the hlyA gene and composed of 529 residues. LLO is a thiol-activated cholesterol-dependent pore forming toxin protein; therefore, it is activated by reducing agents and inhibited by oxidizing agents. Still, LLO differs from other thiol-activated toxins, as its cytolytic activity is maximized at a pH of 5.5. Inside the acidic phagosomes (average pH ~ 5.9) of cells that have phagocytosed L. monocytogenes, LLO is selectively activated by maximizing activity at a pH of 5.5. Following the phagosome lysis by LLO, the bacterium breaks out into the cytosol, where it is able to grow intracellularly, and the toxin has reduced activity in the more basic cytosol. Thus, LLO permits L. monocytogenes to break out from the phagosomes into the cytosol without harming the plasma membrane of the infected cell, which allows the bacteria to live intracellularly, where they are sheltered from extracellular immune system factors such as the complement system and antibodies. LLO also brings about dephosphorylation of histone H3 and deacetylation of histone H4 in the early phases of infection, before entry of L. monocytogenes into the host cell. The pore-forming activity is not implicated in causing the histone modifications. The modifications of the histones affect the down regulation of genes encoding proteins involved in the inflammatory response. Therefore, LLO may be significant in subverting the host immune response to L. monocytogenes. At its NH2-terminus it possesses a 25 residues long typical signal sequence excited during the secretion process. Moreover, in its NH2-terminus there is also a 19 amino acids PEST- like sequence that may target this toxin for degradation. The PEST-like sequence found in LLO and is considered crucial for virulence, given that mutants lacking the sequence lysed the host cell. Nevertheless, contrary to PEST's supposed role in protein degradation, evidence implies that the PEST-like sequence may control LLO production in the cytosol rather than increase degradation of LLO.

Family with Sequence Similarity 84, Member B (FAM84B) coprecipitated with a downstream effector of RAS, CRAF. Binding of FAM83B with CRAF interrupted CRAF/14-3-3 interactions and increased CRAF membrane localization, causing elevated MAPK and mammalian target of rapamycin (mTOR) signaling. FAM84B is an oncogene and possibly represents a new target for therapeutic intervention.

C6ORF108 is stimulated by c-Myc protein that is a transcription factor that is involved in the regulation of cell proliferation, differentiation, and apoptosis. C6ORF108 functions in rat in cellular proliferation and c-Myc-mediated transformation. C6ORF108 catalyzes the cleavage of the N-glycosidic bond of deoxyribonucleoside 5''-monophosphates to yield deoxyribose 5-phosphate and a purine or pyrimidine base. Deoxyribonucleoside 5''-monophosphates comprising purine bases are favored to those comprising of pyrimidine bases.

MAP1LC3B is a member of the MAP1 LC3 family. MAP1LC3B is a subunit of neuronal microtubule-associated MAP1A and MAP1B proteins, that are involved in microtubule assembly and important for neurogenesis. In addition, MAP1LC3B takes part in formation of autophagosomal vacuoles and is expressed mainly in heart, testis, brain and skeletal muscle.

Nephroblastoma Overexpressed (NOV) which is encoded by the NOV gene is a part of the CCN (CTGF/CYR61/NOV) family. NOV takes part in reducing tumorgenicity and proliferation of certain cancer cell lines. NOV interacts with numerous proteins and is involved in both internal and external cell signaling. NOV is expressed in particular tumors, including Wilm’s tumor and most nephroblastomas and is also exerts proangiogenic activities.

RAP2A belongs to the RAS oncogene family and a Ras-like small G protein. The RAP2A protein shares 60% identity with Rap1A and exhibits a carboxy-terminal CAAX motif and 2 upstream cysteines similar to those of the H-Ras, K-Ras and N-Ras proteins. In contrast with Rap1A and Rap1B, overexpression of RAP2A doesn’t obstruct the Ras signaling pathway.

Cholinergic Receptor Nicotinic Alpha 3, also known as CHRNA3 is part of the nicotinic acetylcholine receptor family. Proteins of this family form pentameric complexes comprised of both alpha & beta subunits. Furthermore, CHRNA3 is ligand-gated ions channel which prticipates in neurotransmission. CHRNA3 has been associated with an increased risk of smoking initiation as well as an increased susceptibility to lung cancer.

COP9 signalosome complex subunit 8 isoform 1 (COPS8) is one of the 8 subunits of COP9 signalosome, which is a much conserved protein complex that functions as an imperative regulator in multiple signaling pathways. The structure and function of COP9 signalosome is analogous to that of the 19S regulatory particle of 26S proteasome. COP9 signalosome interacts with SCF-type E3 ubiquitin ligases and acts as a positive regulator of E3 ubiquitin ligases.

Transcription Elongation Factor A (SII)-Like 7 (TCEAL7) has a role in the negative regulation of NF-kappa-B signaling at the basal level by controlling transcriptional activity of NF-kappa-B on its target gene promoters. TCEAL7 links with cyclin D1 promoter containing Myc E-box sequence and transcriptionally inhibits cyclin D1 expression. TCEAL7 regulates telomerase reverse transcriptase expression and telomerase activity in both alternative lengthening of telomeres (ALT) and telomerase-positive cell lines. TCEAL7 is highly expressed in normal and fetal brain tissues, and weakly expressed in the uterus and ovary. TCEAL7 is down-regulated in epithelial ovarian, cervical, prostate, breast, brain and lung cancer cell lines and in the brain and ovarian tumors.

Sialic acid-binding Ig-like lectin 6 isoform 1 (SIGLEC6) is a member of immunoglobulin superfamily and SIGLEC (sialic acid binding Ig-like lectin) family. SIGLEC6 mediates sialic-acid dependent binding to cells and binds to alpha-2, 6-linked sialic acid. The SIGLEC6 protein localizes in numerous compartments such as membrane fraction, extracellular region and so on. The SIGLEC6 receptor binds sialyl-TN glycans and leptin. Placental expression SIGLEC6 is upregulated in preeclampsia.

Chemokine (C-X-C motif) ligand 3 (CXCL3) is a small cytokine belonging to the CXC chemokine family that is also known as GRO3 oncogene (GRO3), GRO protein gamma (GROg) and macrophage inflammatory protein-2-beta (MIP2b). CXCL3 controls migration and adhesion of monocytes and mediates it effects on its target cell by interacting with a cell surface chemokine receptor called CXCR2. The gene for CXCL3 is located on chromosome 4 in a cluster of other CXC chemokines.

WIF1 binds to wnt proteins and inhibits their activities. WIF1 plays a role in mesoderm segmentation. WNT proteins are extracellular signaling molecules that take part in the control of embryonic development & cancer. WIF1 protein contains a WNT inhibitory factor (WIF) domain and 5 epidermal growth factor (EGF)-like domains. WIF1 takes part in mesoderm segmentation. WIF1 protein is found to be present in fish, amphibia and mammals. WIF1 is a recurrent target in human salivary gland oncogenesis. Downregulation of WIF1 takes part in the development and progression of pleomorphic adenomas. WIF1 is a tumor suppressor, specifically in nonfunctioning pituitary tumors.

ASB13 belongs to the ankyrin repeat and SOCS box-containing (ASB) family of proteins which contains ankyrin repeat sequence and a SOCS box domain. ASB13 is a protein coding gene that plays a role as a substrate-recognition part of a SCF-like ECS E3 ubiquitin-protein ligase complex which arbitrates the ubiquitination and subsequent proteasomal degradation of target proteins.

GroEL, HSP60 is a chaperonin located in the mitochondria which is responsible for the transportation & refolding of proteins from the cytoplasm directly into the mitochondrial matrix. GroEL is regulated by the HSP10 cochaperonin, which is a single heptameric protein ring having a molecular mass of 10 kDa which form a unique complex with HSP60. HSP10, GroES coordinates the ATPase activity of the HSP60 subunits in order to allow the release of bound polypeptide in a manner that is productive for its correct folding.

Zinc-alpha-2-glycoprotein (ZAG) is found in body fluids such as serum, sweat, and seminal and breast cyst fluids. It is identical in amino acid sequence to tumor-derived lipid mobilizing factor (LMF), a protein associated with the dramatic loss of adipose body stores in cancer cachexia, and has been shown to stimulate lipolysis by adipocytes in vivo and in vitro. A role for ZAG has been proposed in the regulation of body weight, and age-dependent changes in genetically influenced obesity, and also it regulates melanin production by normal and malignant melanocytes. It has also recently been classified as a novel adipokine in that it is produced by both white and brown fat adipocytes and may act in a local autocrine fashion in the reduction of adiposity in cachexia. Controlling ZAG/LMF's activity could be life-saving in the management of certain cancers and other cachexiainducing conditions, and its possible normal role in body fat store homeostasis is deserving of understanding in its own right. ZAG exhibits a class I major histocompatibility complex (MHC) fold but is a soluble protein rather than being anchored to plasma membranes and does not associate with alpha-2-microglobulin in humans. Like antigen-presenting MHC class I proteins, ZAG has an open apical groove, and X-ray crystallography of human derived ZAG revealed an unidentifiable electron density in a similar position to that occupied by antigenic peptides in classical MHC proteins and glycolipids in isoforms of CD1. This presumptive ligand is not a peptide, and the groove is too small to hold a glycolipid such as is presented by CD1 isoforms. By analogy with all other MHC class I-related proteins that have an open apical groove [some do not ], occupancy by a ligand is probably crucial to ZAG's biological function. Despite all of the structural and biochemical evidence that ZAG binds a ligand, none has so far been found by extraction from protein isolated from biological fluids. This difficulty could be because the ligand is labile, heterogeneous, or readily lost during purification procedures. Knowing more about how ZAG interacts with the compounds it has been found to bind, both natural and artificial, will inform searches for the elusive ligand(s) and its/their role in ZAG's signaling function.

Leukocyte Immunoglobulin Like Receptor B1 (LILRB1) is a member of the leukocyteimmunoglobulinlike receptor (LIR) family. LILRB1is expressed on immune cells, binds to MHC classI molecules on antigen-presenting cells and transduces a negative signal that inhibits stimulation of an immuneresponse. LILRB1 controls inflammatory responses and cytotoxicity to help focus the immune responseand limit autoreactivity. LILRB1 is also expressed on the surface of B cells and monocytes, subsets of NKcells, gamma δ T cells,memory/effector CD8+ T cells and monocyte-derived dendritic cells.

YWHAB belongs to the 14-3-3 family of proteins which are in charge for signal transduction by binding to phosphoserine-containing proteins. YWHAB is found in both plants and mammals. YWHAB protein interacts with RAF1 and CDC25 phosphatases,thus linking mitogenic signaling and the cell cycle machinery. YWHAB is an adapter protein involved in the regulation of a large spectrum of both general and specialized signaling pathway. YWHAB binds to a large number of proteins by recognition of a phosphoserine or phosphothreonine motif. Binding generally results in the modulation of the activity of the binding partner.