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Fetuin is a liver-produced negative acute phase protein composed of two subunits, the A and B chains.
Fetuin homologs have been identified in several species including rat, sheep, pig, rabbit, guinea pig, cattle, mouse and human. Multiple physiological roles for these homologs have been suggested, including ability to bind to hydroxyapatite crystals and to specifically inhibit the tyrosine kinase (TK) activity of the receptor (IR).
Fetuin-A (alpha2-Heremans-Schmid glycoprotein; AHSG) is an important circulating inhibitor of calcification in vivo, and is downregulated during the acute-phase response.
Sera from patients on long-term dialysis with low AHSG concentrations showed impaired ex-vivo capacity to inhibit CaxPO4 precipitation.
Fetuin may influence the resolution of inflammation by modulating the phagocytosis of apoptotic cells by macrophages.
ASHG blocks TGF-beta-dependent signaling in osteoblastic cells, and mice lacking ASHG display growth plate defects, increased bone formation with age, and enhanced cytokine-dependent osteogenesis.

SRP54 is a 54-kDa subunit of the signal recognition particle (SRP), a cytoplasmic ribonucleoprotein complex which leads the translocation of newly synthesized secretory proteins from the polysome to the endoplasmic reticulum. SRP is composed of six polypeptides and a tRNA-like molecule known as 7SL RNA. SRP54 is a GTP-binding protein that directly binds the signal sequences of nascent secretory and membrane proteins. Anti-SRP autoantibodies take place in patients with an autoimmune chronic muscle inflammation called polymyositis. These auto-antibodies predominantly recognize the SRP54 subunit and in addition are able to immunoprecipitate several of the SRP subunits and the RNA component. Nearly 5% of myositis patients are positive for anti-SRP autoantibodies, increasing to 18% in the subgroup of Jo-1 autoantibody-negative patients. The classic 'anti-SRP syndrome' is a severe form of polymyositis in which the myositic inflammation is acute and aggressive onset, with common myalgias and cardiac involvement. Normally there is a poor reaction to therapy with a 5-year survival rate of about 25%.

FGF12 is part of the Fibroblast Growth Factor (FGF) family which has a vast mitogenic and cell survival functions, and play a role in a range of biological activities, among them are embryonic development, cell growth, morphogenesis, tissue repair, tumor growth, and invasion. FGF-12 doesn’t obtain the N-terminal signal sequence present in the majority of the FGF family members, but it contains clusters of basic residues that act as a nuclear localization signal. When transfected into mammalian cells, FGF12 accumulated in the nucleus, but was not secreted. FGF12 is involved in nervous system development and function. FGF12 binds to IB2 (islet brain-2), a cellular kinase scaffold, and voltage gated sodium channels and is also involved in intracellular signalling and ion exchange.

Phosphoglycolate phosphatase (PGP) is discovered in all tissues including red cells, lymphocytes and cultured fibroblasts (at protein level). PGP is most active in skeletal muscle and cardiac muscle. The catalytic activity of PGP is 2-phosphoglycolate + H2O = glycolate + phosphate. Diseases associated with PGP include tardive dyskinesia and polycystic kidney disease.

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.

Fibronectin Type III Domain Containing 5 (Irisin) is a newly discovered hormone, secreted into circulation by muscle, which acts on white adipocytes and promotes WAT “browning”. r-Irisin can reduce body weight and cause induction of brown adipocyte in vivo, including a capacity for thermogenic energy expenditure mediated by uncoupling protein 1 (UCP-1). Irisin mature protein is comprised of 110 amino acid residues and two potential glycosylation sites. High levels of Irisin can be found in the heart whereas Very low expression is found in the colon, pancreas and spleen, if any.

PRKCI, AKAPKC iota, is part of serine/threonine protein kinases family. It takes a key regulatory role in a number of cellular functions including hormone secretion,cell growth differentiation, and gene expression. It is involved in cell polarization processes and the formation of epithelial tight junctions.This protein kinase is calcium-independent and phospholipid-dependent. It is also implicated in the activation of several signal-pathways such as Ras, and NF-kappa-B, c-Src pathways.

Heat-stable enterotoxins (STa) are small, cysteine-rich peptides secreted by Escherichia coli that are able to induce diarrhea through the stimulation of an intestine-specific receptor-guanylyl cyclase known as STaR. Binding of STa to STaR induces a dramatic increase in the cGMP content of the cell; the increase, in turn, inhibits salt absorption and stimulates chloride secretion. This imbalance of ions is accompanied by a massive accumulation of water in the gut that gives rise to the diarrhea and dehydration characteristic of enterotoxin activity. The identification of a receptor for STa on intestinal brush border membranes suggested the existence of an endogenous activator, described guanylin, a 15-amino acid peptide purified from rat small intestine, as a potential ligand for the STaR. This peptide shares sequence similarity with STa; see also uroguanylin. The molecular cloning of the human and mouse cDNAs encoding guanylin was reported. The sequences demonstrated that guanylin is present at the C-terminal end of a larger precursor protein. Expression in mammalian cells indicated that the 94- amino acid proguanylin is inactive. The biologically active guanylin can be released by either chemical or enzymatic treatment of proguanylin. By Northern blot analysis and in situ hybridization, showed that expression of guanylin mRNA is restricted to cells of the intestinal epithelium, specifically the Paneth cells at the base of the small intestinal crypts. These results demonstrate that guanylin is an endogenous activator of STaR isolated a cDNA encoding an apparent precursor of guanylin from a human intestinal cDNA library. The mRNA was expressed at high levels in human ileum and colon. In the mouse, interspecific backcross analysis used to map the Guca2 gene to the distal half of mouse chromosome 4 in a region of homology with human chromosome 1p. By fluorescence in situ hybridization mapped the GUCA2 gene to human 1p35-p34 Guanylin is thought to modulate intestinal water/electrolyte transport in a paracrine mode reported the nucleotide sequence of the gene, the characteristics of its circulating molecular form, and its localization in enterochromaffin cells of the gut. The gene, approximately 2.6 kb in size, consists of 3 exons interrupted by 2 introns. The hormonal form of guanylin is a 94-amino acid peptide with a molecular mass of 10.3 kDa. Guanylin is synthesized by gut enterochromaffin cells as a prohormone of 115 amino acids and is processed to the molecular form of 94 amino acids circulating in the blood.

Galectins are a family of animal lectins with an affinity for beta-galactosides. This family has at least 14 identified members. Galectins share similarities in the CRD (the carbohydrate recognition domain). Galectins are synthesized as cytosolic proteins. Though localized principally in the cytoplasm and lacking a classical signal peptide, galectins can also be stimulated to secretion by non-classical pathways or alternatively targeted to the nucleus. Galectins are involved in modulating cell-cell and cell-matrix interactions. Galectin-8 is a tandem-repeat-type member of the galectin family, consisting of 2 CRDs attached by a linker peptide. Galectin-8 is greatly expressed in lung carcinomas, a number of forms of prostate carcinomas, in addition to other tumor cells. Galectin-8 attaches to a subset of cell surface integrins to modulate ECM-integrin interactions. Once immobilized, Galectin-8 promotes cell adhesion by ligation and clustering of cell surface integrin receptors. On the other hand, as a soluble ligand, Galectin-8 can inhibit cell adhesion.

Hepatitis A virus cellular receptor 1 (HAVCR1) is a membrane receptor for both human hepatitis A virus (HHAV) and TIMD4. HAVCR1 is a type I trans-membrane structural glycoprotein located in the renal proximal tubule epithelial cells. HAVCR1 protein may be involved in the control of asthma and allergic diseases. The reference genome represents an allele which retains a MTTVP amino acid segment that presents defense against atopy in HHAV seropositive individuals.

Vitronectin (VTN) which is a part of the pexin family is a cell adhesion and spreading factor found in serum and tissues. VTN interacts with glycosaminoglycans and proteoglycans. VTN inhibits the membrane-damaging effect of the terminal cytolytic complement pathway and binds to numerous serpin serine protease inhibitors. Scientists have been noticed an over expression of VTN, integrins and plasminogen in migrating cells during wound healing.

Recoverin is a member of the recoverin family of neuronal calcium sensors. Recoverin is a heterogeneously acylated calcium-binding and intracellular signal transduction 23kDa protein in the photoreceptor cells of retina. Recoverin contains four EF-hands, of which two bind Ca. Ca-induced extrusion of the acyl group from a hydrophobic cleft in the protein drives the translocation of recoverin from solution to the disc membrane. Recoverin may prolong the termination of the phototransduction cascade in the retina by blocking the phosphorylation of photo-activated rhodopsin. Recoverin plays a key role in the inhibition of rhodopsin kinase, a molecule that regulates the phosphorylation of rhodopsin. This in due course controls the ability of the eye to adapt to, and recover from, exposure to the presence of light. Recoverin is a detectable serologic protein that is expressed in patients with cancer-associated retinopathy, a paraneoplastic syndrome.

Resistin, a product of the RSTN gene, is a peptide hormone belonging to the class of cysteine-rich secreted proteins which is termed the RELM family, and is also described as ADSF (Adipose Tissue- Specific Secretory Factor) and FIZZ3 (Found in Inflammatory Zone). Human resistin contains 108 amino acids as a prepeptide, and its hydrofobic signal peptide is cleaved before its secretion. Resistin circulates in human blood as a dimeric protein consisting of two 92 amino acid polypeptides, which are disulfide-linked via Cys26.
Mouse resistin, specifically produced and secreted by adipocyte, acts on skeletal muscle myocytes, hepatocytes and adipocytes themselves so that it reduces their sensitivity. Steppan et al. have suggested that resistin suppresses the ability to stimulate glucose uptake. They have also suggested that resistin is present at elevated levels in blood of obese mice, and is down regulated by fasting and antidiabetic drugs. Way et al., on the other hand, have found that resistin expression is severly suppressed in obesity and is stimulated by several antidiabetic drugs.
Other studies have shown that mouse resistin increases during the differentiation of adipocytes, but it also seems to inhibit adipogenesis. In contrast, the human adipogenic differentiation is likely to be associated with a down regulation of resistin gene expression.

Chemokine (C-C motif) ligand 14 (CCL14) is a small cytokine belonging to the CC chemokine family. It is also commonly known as HCC-1. It is produced as a protein precursor that is procesed to generate a mature active protein containing 74 amino acids that and is 46% identical in amino acid composition to CCL3 and CCL4. This chemokine is expressed in various tissues including spleen, bone marrow, liver, muscle, and gut. CCL13 activates monocytes, but does not induce their chemotaxis. Human CCL13 is located on chromosome 17 within a cluster of other chemokines belonging to the CC family.

CTACK is a chemotactic factor that attracts skin-associated memory T-lymphocytes. CTACK is involved in mediating homing of lymphocytes to cutaneous sites. CTACK Binds to CCR10.

Major Histocompatibility Complex Class I C (HLA-C) belongs to the HLA class I heavy chain paralogues. The HLA-C (class I molecule) is a heterodimer comprised of a heavy chain and a light chain (beta-2 microglobulin). The heavy chain is anchored in the membrane. Class I molecules have a key role in the immune system by presenting peptides derived from endoplasmic reticulum lumen. Class I molecules are expressed in virtually all cells.

Beta Defensin 118 (DEFB118) which is a member of the beta subfamily of defensins, is found in a cluster with other beta-defensin genes on the long arm of chromosome 20. Beta-defensins are antimicrobial peptides which provide protection for tissues and organs from infection by a diversity of microorganisms. DEFB118 protein’s expression is regulated by androgen, and the encoded protein binds to sperm and exhibits antibacterial activity.

15 KDa Selenoprotein (SEP15) is a protein-coding gene which contains a selenocysteine (Sec) residue at its active site. Theselenocysteine is encoded by the UGA codon that usually signals translation termination. The 3' UTR ofselenoprotein genes have a conventional stem-loop structure, the sec insertion sequence (SECIS), which isnecessary for the recognition of UGA as a Sec codon rather than as a stop signal. Studies in mouse propose thatthis selenoprotein may have redox function and may be implicated in the quality control of protein folding. This geneis localized on chromosome 1p31, a genetic locus usually mutated or deleted in human cancers.Diseases associated with SEP15 include lung cancer susceptibility, and chronic lymphocytic leukemia.

a-Synuclein (amino acids 1-140), an acidic neuronal protein of 140 amino acids, is extremely heat-resistant and is natively unfolded with an extended structure primarily composed of random coils. a-synuclein has been suggested to be implicated in the pathogenesis of Parkinson’s disease and related neurodegenerative disorders, and more recently, to be an important regulatory component of vesicular transport in neuronal cells. Moreover, recent studies have shown that a-synuclein has chaperone activity and that this activity is lost upon removing its C-terminal acidic tail (amino acids 96-140).

SYT13 belongs to the great synaptotagmin protein family which contain 2 domains: cytoplasmic C terminus with two tandem C2 domains (C2A and C2B) and extracellular N-terminal transmembrane domain. Synaptotogmin family members have dissimilar biochemical properties and developmental profiles, and patterns of tissue distribution. Additionally, Synaptotogmins formulate homo- and heteromeric complexes with each other. Synaptotagmins operate as membrane traffickers in multicellular organisms.

PDGF-BB is a member of the platelet-derived growth factor family. The four members of this family are mitogenic factors for cells of mesenchymal origin and are characterized by a motif of eight cysteines. This gene product can exist either as a homodimer (PDGF-BB) or as a heterodimer with the platelet-derived growth factor alpha polypeptide (PDGF-AB), where the dimers are connected by disulfide bonds. Mutations in this gene are associated with meningioma. Reciprocal translocations between chromosomes 22 and 7, at sites where this gene and that for COL1A1 are located, are associated with a particular type of skin tumor called dermatofibrosarcoma protuberans resulting from unregulated expression of growth factor. Two splice variants have been identified for this gene.

GREM1 belongs to the BMP (bone morphogenic protein) antagonist family. Like BMPs, BMP antagonists comprise cystine knots and usually form homo- and heterodimers. The CAN (cerberus and dan) subfamily of BMP antagonists, to which GREM1 belongs, is characterized by a C-terminal cystine knot with an eight-membered ring. The antagonistic effect of the secreted glycosylated protein is because of its direct binding to BMP proteins. As an antagonist of BMP, GREM1 takes a place in regulating organogenesis, body patterning, and tissue differentiation. In mouse, GREM1 has been shown to convey the sonic hedgehog (SHH) signal from the polarizing region to the apical ectodermal ridge during limb bud outgrowth. Alternatively merged transcript variants encoding different isoforms have been found for this gene.

C-type Lectin Domain Family 1 Member B, also known as CLEC1B. NK-Natural killer cells express multiple calcium-dependent (C-type) lectin-like receptors, for instance CD94 (KLRD1; MIM 602894) and NKG2D (KLRC4; MIM 602893), which interact with major histocompatibility complex class I molecules and either inhibit or else activate cytotoxicity and cytokine secretion. CLEC1B is a C-type lectin-like receptor which is expressed in myeloid cells as well as in NK cells.

GH-releasing peptides (GHRPs) are synthetic peptides that like GHRH act directly on pituitary somatotrophs to stimulate GH release. GHRP-2, an investigational drug, is one of the most potent members of the GHRP family. It has been shown to be effective in adults via the oral and intranasal as well as the iv route of administration.