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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.

Methionine sulfoxide reductase B1 (SEPX1 or MSRB1), is a selenoprotein that contains a selenocysteine (Sec) residue at its active site. The selenocysteine is encoded by the UGA codon that usually signals translation termination. SEPX1 is a member of the methionine sulfoxide reductase B (MsrB) family, and is expressed in an assortment of adult and fetal tissues. MSRs (Methionine sulfoxide reductases) catalyze the reduction of free and protein-bound methionine sulfoxides to corresponding methionines. The oxidation of methionine by ROS creates a diastereomeric mixture of methionine-S-sulfoxide (Met-S-SO) and methionine-R-sulfoxide (Met-R-SO). Two separate enzyme families evolved for reduction of these sulfoxides, with methionine-S-sulfoxide reductase (MsrA) being stereospecific for Met-S-SO and methionine-R-sulfoxide reductase (MsrB) for Met-R-SO.

SEPT6 is a member of the septin family of GTPases and is functionally involved in cytokinesis and conservation of cellular morphology. SEPT6 interact with SEPT2. The genes encoding the mixed-lineage leukemia and SEPT2 breakpoint proteins are associated with one type of pediatric acute myeloid leukemia which is caused by reciprocal translocation between chromosomes 11 and X.

Sorting nexin 3 (SNX3) belongs to the large family of hydrophilic proteins, which interact with various receptor types and are involved in intracellular trafficking. SNX3 interacts with phosphatidylinositol-3-phosphate, and is involved in protein trafficking. SNX3 comprises a distinct subgroup of nexins, which share less sequence similarity outside of the PX domain and have significantly different binding affinities for the tyrosine kinase receptors.

TCEB2 is a subunit of the SIIII complex which is a heterotrimer consisting of a transcriptionally active subunit (A) and two regulatory subunits (B and C). TCEB2 initiates elongation by RNA polymerase II by suppressing transient pausing of the polymerase at many sites within transcription units. The von Hippel-Lindau tumor suppressor protein binds to elongins B and C, and thereby inhibits transcription elongation.

Profilin1 (PFN1) is a ubiquitous actin monomer-binding protein which is a member of the profilin family. PFN1 significantly boosts skin wound healing in-vitro and in-vivo which may be mediated by purinergic receptors. PFN1 is also active in endothelial cell migration and vessel sprouting. PFN1 is thought to control actin polymerization in response to extracellular signals. PFN1 binds to actin and affects the formation of the cytoskeleton. In addition, PFN1 has an important role in the regulation of epithelial cell-cell adhesion. At high concentrations, profilin averts the polymerization of actin, while at low concentrations it enhances the polymerization. PFN1 gene deletion is linked to Miller-Dieker syndrome.

Intein is a section of a protein which can remove itself and return the remaining segment with a peptide bond. In addition, Inteins hold an endonuclease domain which takes part in Intein proliferation. Actually, various genes have unrelated intein-coding segments inserted at altered positions and they were found in all three domains of life (eukaryotes, bacteria, and archaea) and in viruses.

CTK-19 is a member of the keratin family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. The type I cytokeratins consist of acidic proteins which are arranged in pairs of heterotypic keratin chains. Unlike its related family members, this smallest known acidic cytokeratin is not paired with a basic cytokeratin in epithelial cells. It is specifically expressed in the periderm, the transiently superficial layer that envelopes the developing epidermis. The type I cytokeratins are clustered in a region of chromosome 17q12-q21.

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.

S100G (calbindin D9K) is a vitamin D-dependent calcium-binding protein. S100G, which is a cytosolic protein, is a member of a family of calcium-binding proteins that includes calmodulin, parvalbumin, troponin C, and S100 protein. In the intestine, S100G is vitamin D-dependent and its expression correlates with calcium transport activity. S100G may increase Ca2+ absorption by buffering Ca2+ in the cytoplasm and increase ATP-dependent Ca2+ transport in duodenal basolateral membrane vesicles.

SORBS3 is an SH3 domain-containing adaptor protein. The existence of SH3 domains in the SORBS3 protein have a role in its capability to attach to other cytoplasmic molecules and contribute to cystoskeletal organization, cell adhesion and migration, signaling, and gene expression. Various transcript variants encoding different isoforms are known for this gene.

NCALD belongs to the neuronal calcium sensor (NCS) family. NCALD is cytosolic at inactive calcium levels; but, high intracellular calcium levels induce a conformational transformation which exposes the myristoyl group, causing protein association with membranes and partial co-localization with the perinuclear trans-golgi network. NCALD protein is a regulator of signal transduction by G protein-coupled receptor.

Energy Homeostasis Associated (ENHO) participates in glucose homeostasis maintenance and lipid metabolism. ENHO is expressed in the liver and the brain. The role of ENHO in obesity or diabetes is studied.

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 a and b 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 a-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, bacteria, complement components, paraoxonase, beta amyloid, leptin and others. Clusterin has been ascribed a plethora of functions such as phagocyte recruitment, aggregation induction, complement attack prevention, apoptosis inhibition, membrane remodeling, lipid transport, hormone transport and/or scavenging, matrix metalloproteinase inhibition.
A genuine function of clusterin has not been defined. One tempting hypothesis says that clusterin is an extracellular chaperone protecting cells from stress induced insults caused by degraded and misfolded protein precipitates.
Clusterin is up- or down regulated on the mRNA or protein level in many pathological and clinically relevant situations including cancer, organ regeneration, infection, Alzheimer disease, retinitis pigmentosa, myocardial infarction, renal tubular damage, autoimmunity and others.

Alpha & Gamma-Adaptin Binding Protein (AAGAB), which is also known as P34, takes part in membrane traffic and interacts with AP1G1 and AP2A1.AAGAB is highly expressed in skin and keratinocytes, with the highest levels in adrenal gland, rectum and thymus.

Vesicle-trafficking protein SEC22b precursor (SEC22B) is a member of the synaptobrevin family. SEC22B forms a complex with SNARE and it is believed to have a role in the ER-Golgi protein trafficking. SEC22B has a strong similarity to the mouse and Chinese hamster proteins.

OTOR proteins is also known as fibrocyte-derived protein (Fdp) and Melanoma inhibitory activity-like (MIAL). Otoraplin is a member of the melanoma-inhibiting activity gene family. Otoraplin is a secreted 16 kDa globular protein that is expressed in the inner ear by periotic mesenchyme and developing and mature fibrocytes. OTOR is highly homologous to MIA/cartilage-derived retinoic acid-sensitive protein (CD-RAP), which is a cartilage-specific protein that is also expressed in malignant melanoma cells. The 111 amino acid mature human otoraplin contains 1 SH3 domain (46 – 107 amino acids) and a Tyr at position 50 that is reportedly sulfated. Otoraplin takes pasrt in the initiation of periotic mesenchyme chondrogenesis.
Otoraplin is secreted through the Golgi apparatus and plays a role in cartilage development and maintenance. A frequent polymorphism in the translation start codon of OTOR can abolish translation and may be associated with forms of deafness.

Calbindin 1 (CALB1) is a calcium binding protein that is a member of the troponin C superfamily. CALB1 plays a vital role in calcium regulation (including calcium transport and uptake, calcification of bone and teeth) and calcium associated signaling in neurons and transiently in embryological development. CALB1 also has a role in protecting neurons from apoptotic cell death. CALB1 buffers cytosolic calcium and may stimulate a membrane Ca2+-ATPase and a 3',5'-cyclic nucleotide phosphodiesterase. The biological function of CALB1 seems to be tied to the redox state of its five cysteine residues.
CALB1 has 4 active calcium-binding domains, and 2 modified domains that seemingly have lost their calcium-binding ability. CALB1 is expressed in neural tissues. In the brain, the CALB1 synthesis is independent of vitamin-D-derived hormones.
Disregulation of the CALB1 is associated with epilepsy, amyotrophic lateral sclerosis, Huntington's disease. The neurons in brains of Huntington disease patients are calbindin-depleted.

Calretinin is an intracellular calcium-binding protein belonging to the troponin C superfamily characterized by a structural motif described as the EF-hand domain. The immunohistochemical detection of calretinin in developing cerebellum is restricted to the later stages indicated by weak staining from week 21 of gestation, in Purkinje and basket cells and in neurons of the dentate nucleus. The intensity of staining increases as the cerebellum matures. In tumors, calretinin has been detected in mesotheliomas and some pulmonary adenocarcinomas.

Cytokeratin 14 is a member of the keratin family, the most diverse group of intermediate filaments. Cytokeratin 14 is a type I keratin, is usually found as a heterotetramer with two keratin 5 molecules, a type II keratin. Together they form the cytoskeleton of epithelial cells. Mutations in the genes for these keratins are associated with epidermolysis bullosa simplex. At least one pseudogene has been identified at 17p12-p11.

TOR1A which is a member of the AAA family of adenosine triphosphatases (ATPases) is associated to the Clp protease/heat shock family and is expressed highly in the substantia nigra pars compacta.TOR1A functions as a molecular chaperone assisting in the suitable folding of secreted and/or membrane proteins. Mutations in TOR1A result in the autosomal dominant disorder, torsion dystonia one.

Recombinant Human Cytokeratin 20 His Tag (KRT20) belongs to the keratin family. The keratins are intermediate filament proteins responsible for the structural integrity of epithelial cells and are subdivided into cytokeratins and hair keratins. The type I cytokeratins is comprised of acidic proteins that are organized in pairs of heterotypic keratin chains. KRT20 is a main cellular protein of mature enterocytes and goblet cells and is specifically expressed in the gastric and intestinal mucosa.

VAMP8 also called endobrevin, is the main component of a SNARE complex involved in the docking and fusion of synaptic vesicles with the presynaptic membrane. VAMP8 protein is involved in the regulatation of enzyme secretion in pancreatic acinar cells and plays a part in the abscission of the midbody during cell division, which leads to completely separate daughter cells. VAMP8 is essential for dense-granule secretion in platelets. VAMP8 is related with the perinuclear vesicular structures of the early endocytic compartment. VAMP8 interacts particularly with the soluble NSF-attachment protein (alpha-SNAP), through an VAMP8-containing SNARE complex.