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Leptin is a protein hormone. It is mainly produced in adipose cells that regulate energy homeostasis by restraining hunger. Leptin ties to nuclear receptors in the hypothalamus (arcuate nucleus). Similar to insulin resistance in type II diabetes, in obesity there is a decrease in the sensitivity towards leptin, ending in a failure to identify satiety, even in high levels of energy stores or leptin itself. Full-length cDNA encoding 2 leptin sequences (tLepA and tLepB) and 1 leptin receptor sequence (tLepR) exists in tilapia (Oreochromis niloticus). The full-length cDNA of tLepR is 3423 bp, encoding a protein of 1140 amino acid which contained all functionally important domains conserved among vertebrate leptin receptors. The cDNAs of tLepA and tLepB are 486 bp and 459 bp in length, encoding proteins of 161 aa and 152 aa, respectively. The three-dimensional structures of tLepA and tLepB demonstrates strong conservation of tertiary structure with that of human leptin comprised of 4 helixes.

A 16-kDa peptide hormone secreted from white adipocytes and implicated in the regulation of food intake and energy balance. Leptin provides the key afferent signal from fat cells in the feedback system that controls body fat stores.

Neurotensin (NTS) is a common precursor for 2 peptides, neuromedin N and neurotensin. Neurotensin is a secreted tridecapeptide, which is generally distributed throughout the central nervous system, and may serve as a neurotransmitter or a neuromodulator. NTS is involved in dopamine-associated pathophysiological events, in the maintenance of gut structure and function, and in the regulation of fat metabolism. Tissue-specific processing may initiate the formation in some tissues of larger forms of neuromedin N and neurotensin. The large forms may embody more stable peptides which are also biologically active.

Peptidase Inhibitor 3, also referred to PI3, is neutrophil and pancreatic elastase-specific inhibitor of skin. The protein may prevent elastase mediated tissue proteolysis. PI3 has shown inhibition of alpha-4-beta-2/CHRNA2-CHRNB2 nicotinic acetylcholine receptor, a weak inhibition on Kv11.1/KCNH2/ERG1 and on the transient receptor potential cation channel subfamily V member 1.

ASF1A is part of the H3/H4 family of histone chaperone proteins corresponding to the anti-silencing function-1 gene in yeast. ASF1A is an important element of the histone donor complex that functions in nucleosome assembly. ASF1A interacts with histones H3 and H4, and functions together with a chromatin assembly factor during DNA replication and repair. Deletion of ASF1A in yeast and Drosophila confers sensitivity to various DNA damaging agents and inhibitors of DNA replication, increases genomic instability and sister chromatid exchange, and activates the DNA damage checkpoint.

Plasma protease C1 inhibitor (SERPING1) is a part of the serpin superfamily of serine protease inhibitors. SERPING1 plays an important role in regulating activation of both the complement and contact systems. That isdue to the fact that SERPING1 regulates the activation of complement factor C1 in addition to the activity of activated C1 by coupling with the active catalytic site at the light chains of C1r and C1s. SERPING1 insufficiency results in hereditary angioedema, which is characterized by recurrent episodes of localized angioedema of the skin, gastrointestinal mucosa or upper respiratory mucosa.

CD207 (C-type lectin domain family 4 member K) is expressed in Langerhans cells which are immature dendritic cells of the epidermis and mucosa. Moreover, CD207 is expressed in several other dendritic cell types including dermal CD103+ DCs and splenic CD8+ DCs. Langerin is localized in the Birbeck granules, the organelles present in the cytoplasm of Langerhans cells and comprised of superimposed and zippered membranes. CD207 is a C-type lectin with mannose binding specificity, and it has been suggested that mannose binding by the CD207 protein leads to internalization of antigen into Birbeck granules thus providing access to a nonclassical antigen-processing pathway.

Furin is a member of the peptidase S8 family. Furin signifies the ubiquitous endoprotease activity within constitutive secretory pathwaysas well as capable of cleavage at the RX (K/R) R consensus motif.Furin is considered to be one of the proteases responsible for the activation of HIV envelope glycoproteins gp160 as well as gp140 and might take part in tumor progression. Among the diseases associated with FURIN are dementia, familial british and plague.

Vaspin (visceral adipose-specific SERPIN) is a newly identified adipokine, which is a member of serine protease inhibitor family. Vaspin is also a unique insulin sensitizing adipocytokine in obesity. A recent publication indicates that induction of human vaspin mRNA expression in adipose tissue is regulated in a fat depot-specific manner and could be associated with parameters of obesity, insulin resistance, and glucose metabolism.

Clusterin also named Apolipoprotein J (APO-J) is a 75-80 kD disulfide-linked heterodimeric protein containing about 30% of N-linked carbohydrate rich in sialic acid but truncated forms targeted to the nucleus have also been identified. The precursor polypeptide chain is cleaved proteolytically to remove the 22-mer secretory signal peptide and subsequently between residues 227/228 to generate the ? and ? chains. These are assembled in anti-parallel to give a heterodimeric molecule in which the cysteine-rich centers are linked by five disulfide bridges and are flanked by two predicted coiled-coil ? -helices and three predicted amphipathic a-helices. Across a broad range of species clusterin shows a high degree of sequence homology ranging from 70% to 80%. It is nearly ubiquitously expressed in most mammalian tissues and can be found in plasma, milk, urine, cerebrospinal fluid and semen. It is able to bind and form complexes with numerous partners such as immunoglobulins, lipids, heparin, b

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.

Nucleobindin-2 (also known as NUCB2 or Nesfatin) is a EF-hand calcium-binding protein. Nucleobindin-2 takes part in calcium homeostasis and is a multifunctional protein that interacts with Ca(2+) nucleic acids & various regulatory proteins in different signaling pathways. NUCB2 (Nesfatin) is localized in neuronal perikarya and dendrites of mouse brain.

Cystatins are a superfamily of cysteine proteinase inhibitors found in both plants and animals. They comprise a group of proteinase inhibitors, widely distributed in tissues and body fluids, and form tight complexes with cysteine proteases such as cathepsin B, H, L and S. Cystatin C, a secreted molecule of this family, is of interest from biochemical, medicine and evolutionary points of view. Cystatin C is increased in patients with malignant diseases, and is related to the insufficiency of renal function and appears to be a better marker than creatinine. On the other hand, low levels of cystatin C involve cause the breakdown of the elastic laminae and subsequently, the atherosclerosis and abdominal aortic aneurysm.

Leptin is a protein hormone with important effects in regulating body weight, metabolism and reproductive function. The protein is approximately~16 kDa in mass and encoded by the obese (ob)gene. leptin is expressed predominantly by adipocytes, which fits with the idea that body weight is sensed as the total mass of fat in the body. Smaller amounts of leptin are also secreted by cellsin the epithelium of the stomach and in the placenta. Leptin receptors are highly expressed in areas of the hypothalamus known to be important in regulating body weight, as well as in T lymphocytes and vascular endothelial cells.

Vimentin expression in human malignant glioma cells depends on cellular density, algorithms of drug delivery and chemo/radio treatment. Vimentin and detyrosinated microtubules provide structural support for the extensive microtentacles observed in detached tumor cells and a mechanism to promote successful metastatic spread. Primary colorectal carcinomas display aberrant expression of vimentin, and have activated Notch and TGFbeta signaling pathways. Vimentin is a strong arterial substrate for transglutaminases. Transglutaminase-mediated vimentin dimerization results in a novel unifying pathway by which vasodilatory and remodeling responses may be regulated. Ablation of vimentin expression inhibits migration and invasion of colon and breast cancer cell lines. Vimentin is the main intermediate filament protein in mesenchymal cells and is therefore of value in the differential diagnosis of undifferentiated neoplasms.

Prohibitin (PHB) is an evolutionarily conserved gene that is ubiquitously expressed and which Mutations have been linked to sporadic breast cancer. PHB is thought to be a negative regulator of cell proliferation and may be a tumor suppressor. Prohibitin is expressed as two transcripts with changeable lengths of 3' untranslated region. The longer transcript is present at higher levels in proliferating tissues and cells, proposing that this longer 3' untranslated region functions as a trans-acting regulatory RNA.

Vimentin expression in human malignant glioma cells depends on cellular density, algorithms of drug delivery and chemo/radio treatment. Vimentin and detyrosinated microtubules provide structural support for the extensive microtentacles observed in detached tumor cells and a mechanism to promote successful metastatic spread. Primary colorectal carcinomas display aberrant expression of vimentin, and have activated Notch and TGFbeta signaling pathways. Vimentin is a strong arterial substrate for transglutaminases. Transglutaminase-mediated vimentin dimerization results in a novel unifying pathway by which vasodilatory and remodeling responses may be regulated. Ablation of vimentin expression inhibits migration and invasion of colon and breast cancer cell lines.

Renin is a highly specific endopeptidase which generates angiotensin I from angiotensinogen in the plasma. angiotensin I is an important regulator of blood pressure and electrolyte balance. Renin initiates a cascade of reactions that produce an elevation of blood pressure and increased sodium retention by the kidney.

Dsb proteins are in charge for the formation and rearrangement of disulfide bonds during the folding of secreted and membrane proteins in bacteria. DsbG has disulfide bond isomerase and chaperone activity. DsbG interacts with refolding intermediates of chemically denatured citrate synthase and prevents their aggregation in vitro. DsbG shares sequnce homology with DsbC. DsbG forms a stable periplasmic dimer and displays an equilibrium constant with glutathione comparable with DsbA and DsbC. DsbG is expressed at roughly 25% level of DsbC.

Activins are homodimers or heterodimers of the different ? subunit isoforms, part of the TGF? family. Mature Activin A has two 116 amino acids residues betaA subunits (bA-bA). Activin displays an extensive variety of biological activities, including mesoderm induction, neural cell differentiation, bone remodelling, haematopoiesis, and reproductive physiology. Activins takes part in the production and regulation of hormones such as FSH, LH, GnRH and ACTH. Cells that are identified to express Activin A include fibroblasts, endothelial cells, hepatocytes, vascular smooth muscle cells, macrophages, keratinocytes, osteoclasts, bone marrow monocytes, prostatic epithelium, neurons, chondrocytes, osteoblasts, Leydig cells, Sertoli cells, and ovarian granulosa cells.

Desmin is a muscle-specific class III intermediate filament. Homopolymers of this protein form a stable intracytoplasmic filamentous network connecting myofibrils to each other and to the plasma membrane. Mutations in this gene are associated with desmin-related myopathy, a familial cardiac and skeletal myopathy (CSM), and with distal myopathies.