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Fc Fragment Of IgA Receptor, also known as FCAR, is part of the multichain immune recognition receptor family which is the most abundant immunoglobulin in mucosal areas however it is only the second most common antibody isotype in serum. FCAR participates in both pro-and anti-inflammatory responses depending on the state of IgA bound. FCAR is also a vital Fc receptor for neutrophil killing of tumor cells. Once FCAR expressing neutrophils interact with IgA-opsonized tumor cells, the neutrophils not only show antibody-dependent cell-mediated cytotoxicity, but also release the cytokines TNF-α and IL-1β which cause increased neutrophil migration to the site.

Vacuolar protein sorting-associated protein 26A (VPS26A) is a vital element of the retromer complex, which is required to recover lysosomal enzyme receptors (IGF2R and M6PR) from endosomes to the trans-Golgi network. Furthermore, VPS26A is essential in the regulation of transcytosis of the polymeric immunoglobulin receptor (pIgR-pIgA). Expression analysis in yeast and mammalian cells reveal that VPS26A interacts directly with VPS35 that functions as the core of the retromer complex.

V-set and transmembrane domain containing 2 (VSTM2L) is a novel modulator of HN neuroprotective activity. VSTM2L colocalizes with HN in distinct brain areas as well as in primary cultured neurons, where it plays a part in the modulation of neuronal viability. When tested in HN neuroprotection bioassays, VSTM2L acts as a potent antagonist of HN neuroprotective activity. The VSTM2L protein is the first example of a secreted antagonist of HN and may have a role in the modulation of HN biological functions.

Synaptojanin 2 Binding Protein (SYNJ2BP) contains 1 PDZ (DHR) domain which binds to isoform 2A of SYNJ2 (through the unique motif in the C-terminus) and interacts with MAPK12.

AK3L1 is an affiliate of the adenylate kinase family of enzymes. AK3L1 enzyme is restricted to the mitochondrial matrix. Adenylate kinases-3 regulates the adenine and guanine nucleotide compositions within a cell by means of catalyzing the reversible transfer of phosphate group among these nucleotides. 5 different isozymes of adenylate kinase have been identified in vertebrates. The enzyme expression of various adenylate kinase isozymes is growth regulated and tissue-specific.

Gankyrin (proteasome 26S subunit) is a multicatalytic proteinase oncoprotein commonly overexpressed in most hepatocellular carcinomas. Proteasomes are found throughout eukaryotic cells at a high concentrations and cleave peptides in an ATP/ubiquitin-dependent process in a non-lysosomal pathway. Gankyrin interacts with S6 ATPase of the 19S regulatory particle of the 26S proteasome. Gankyrin is involved in theregulation of the phosphorylation of the retinoblastoma protein by CDK4, and to enhance the ubiquitinylation of p53 by MDM2. Gankyrin consists of 7 ankyrin repeats and is structurally similar to I kappa Bs. Gankyrin acts as a regulatory subunit of the 26s proteasome which is involved in the atp-dependent degradation of ubiquitinated proteins. Gankyrin is involved in progression of esophageal squamous cell carcinoma. gankyrin plays an oncogenic role especially in early stages of human epatocarcinogenesis. Gankyrin binds to NF-kappaB and suppresses its activity at the transcription level by modulating acetylation through SIRT1. Structural comparison between Gankyrin & p16(INK4A) identified numerous residues of gankyrin that are potentially important for CDK4 binding.

Endothelial cells express three different vascular endothelial growth factor (VEGF) receptors, belonging to the family of receptor tyrosine kinases (RTKs). They are named VEGFR-1 (Flt-1), VEGFR-2 (KDR/Flk-1), VEGFR-3 (Flt-4). Their expression is almost exclusively restricted to endothelial cells, but VEGFR-1 can also be found on monocytes. All VEGF-receptors have seven immunoglobulin-like extracellular domains, a single transmembrane region and an intracellular split tyrosine kinase domain. VEGFR-2 has a lower affinity for VEGF than the Flt-1 receptor, but a higher signaling activity. Mitogenic activity in endothelial cells is mainly mediated by VEGFR-2 leading to their proliferation.
Differential splicing of the flt-1 gene leads to the formation of a secreted, soluble variant of VEGFR-1 (sVEGFR-1). No naturally occuring, secreted forms of VEGFR-2 have so far been reported. The binding of VEGF165 to VEGFR-2 is dependent on heparin.

OVCA2 is a member of the UPF0483 family. Universally expressed, the OVCA2 expression is regulated by retinoids. OVCA2 cooperates with apoptosis-related protein Bag-1, which indicates that OVCA2 takes part in cell proliferation. OVCA2 is thought to perform as a serine-hydrolase due to its catalytic and structural characteristics. Additionally, OVCA2 is believed to be involved in tumor suppression because of its reduced expression in ovarian and other tumor cell lines.

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.

AXIN1 is a cytoplasmic protein, which contains a regulation of G-protein signaling (RGS) domain and a dishevelled and axin (DIX) domain. Axin1 is has been characterized as a tumor suppressor. In addition, Axin1 has an essential role in the formation of the embryonic neural axis. It has also been reported that Axin is found in mitotic spindles and centrosomes. AXIN1 interacts with adenomatosis polyposis coli, catenin beta-1, glycogen synthase kinase 3 beta, protein phosphate 2, and itself. AXIN1 functions as a negative regulator of the WNT1 signaling pathway and is able to induce apoptosis. Axin can be identified in a mouse mutant strain, created by random integration of a transgene. Mutations in the AXIN1 gene are linked to hepatocellular carcinoma, hepatoblastomas, ovarian endometriod adenocarcinomas, and medullablastomas.

Flagellin arranges itself in a hollow cylinder to create the filament in bacterial flagellum. Flagellin is the key substituent of bacterial flagellum, and is found in large quantities on almost all flagellated bacteria.

Chromgranin-A is part of the neuroendocrine secretory protein family. CHGA is located in secretory vesicles of neurons and endocrine cells. Chromgranin-A is a precursor to three biologically active peptides; vasostatin, pancreastatin, and parastatin. These peptides act as autocrine or paracrine negative modulators of the neuroendocrine system. Other peptides, including chromostatin, beta-granin, WE-14 and GE-25, are also derived from the full-length protein. Chromgranin-A has numerous biological activities on some tissues and organs and exerts a large spectrum of homeostatic actions, including antifungal and antimicrobial effect, modulation of cell adhesion, and inhibition of parathyroid hormone secretion.

ATF1, a cyclic-AMP dependent transcription factor, is expressed in a large selection of cell types and can dimerize with CREB. MSK1 and MSK2 protein kinases are essential for the stress-induced phosphorylation of transcription factors CREB and ATF1 in primary embryonic fibroblasts. Epidermal growth factor induction of c-jun expression needs ATF1 and MEF2 sites in the c-jun promoter.

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.
Resistin may be an important link between obesity and insulin resistance. Mouse resistin, specifically produced and secreted by adipocyte, acts on skeletal muscle myocytes, hepatocytes and adipocytes themselves so that it reduces their sensitivity to insulin. Steppan et al. have suggested that resistin suppresses the ability of insulin 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.

EBI3 has an induced expression in B lymphocytes in reaction to Epstein-Barr virus infection. EBI3 encodes a secreted glycoprotein belonging to the hematopoietin receptor family, and heterodimerizes with a 28 kDa protein to form iIL-27. EBI3 drives rapid clonal expansion of naive cd4(+) t-cells. EBI3 strongly synergizes with IL-12 to activate IFN-gamma production of naive cd4(+) t-cells. EBI3 mediates its biologic effects through the cytokine receptor wsx-1/tccr.

Ataxin 3 is otherwise known as Machado-Joseph disease protein 1. Machado–Joseph disease is a hereditary autosomal dominant neurodegenerative disorder. ATXN3 contains trinucleotide CAG repeats in the coding region, and the expansion of these repeats from the normal 13-36 to 68-79 causes the Machado-Joseph disease. ATXN3 is a poly-ubiquitin-binding protein whose cellular turnover is regulated by its catalytic activity.
In addition, ATXN3 is a proteasome-associated factor which mediates the degradation of ubiquitinated proteins. ATXN3 folds reversibly using a single intermediate; partial destabilization of ATXN3 by chemical denaturation causes the formation of fibrillar aggregates by the non-pathological variant.
Ataxin-3 interacts with the major histone acetyltransferases cAMP-response-element binding protein (CREB)-binding protein, p300, and p300/CREB-binding protein-associated factor and hinders transcription by these coactivators.

Inhibins are dimeric peptide hormones produced by female ovarian granulose cells and male Sertoli cells as well as a variety of other tissues. Inhibins have two isoforms, A and B, with the same alpha subunit but different beta subunits. Inhibin A is a dimer of alpha and beta A subunits, inhibin B is a dimer of alpha and beta B subunits.
Inhibins are thought to inhibit the production of follicle-stimulating hormone (FSH) by the pituitary gland. In addition, Inhibins are also thought to play a role in the control of gametogenesis, and embryonic and fetal development.

BETV4 is primarily expressed in mature birch (Betula verrucosa) pollen and Causes an allergic reaction in human. BETV4 is a calcium-binding protein of 2-EF-hand type, which is exists in pollen of various plant species. This cross-reactivity can serve as a marker allergen for plant polysensitization.

Persephin is a member of the GDNF ligand subfamily of the TGF-beta superfamily. PSPN encourages the existence and growth of key dopaminergic and motor neurons, as well as taking part in kidney development. Nonetheless, persephin does not support existence of peripheral neurons.

Septin-3, also known as SEPT3 is a member of the septin family of GTPases. Members of this family are essential for cytokinesis. Furthermore, expression is up regulated by retinoic acid in a human teratocarcinoma cell line. The exact role of SEPT3 has not been determined yet. In addition, among its related pathways are Bacterial invasion of epithelial cells.

EBI3 has an induced expression in B lymphocytes in reaction to Epstein-Barr virus infection. EBI3 encodes a secreted glycoprotein belonging to the hematopoietin receptor family, and heterodimerizes with a 28 kDa protein to form iIL-27. EBI3 drives rapid clonal expansion of naive cd4(+) t-cells. EBI3 strongly synergizes with IL-12 to activate IFN-gamma production of naive cd4(+) t-cells. EBI3 mediates its biologic effects through the cytokine receptor wsx-1/tccr.

UBTD2 is an ubiquitin (Ub) domain-containing protein, originally recognized in dendritic cells, that takes part in ubiquitination pathway. Ubiquitin is the best understood post-translation modifier; however, there is a growing family of ubiquitin-like proteins (UBLs) who change cellular targets in a pathway. UbL proteins take part in a variation of cellular courses, like DNA repair, protein sorting, protein degradation, cell division, apoptosis and autophagy.

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.