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S100b is a member of the S100 family of proteins which are a family of EF-hand calcium binding proteins that exist mostly as dimers of the 20 currently identified individual S100 monomers. The S100B homodimer is expressed in cells of the central nervous system, glial cells and in certain peripheral cells e.g. Schwann cells, melanocytes, adipocytes and chondrocytes. S100 proteins are localized either in the cytoplasm or the nucleus of a wide range of cells. S100 proteins are involved in the regulation of a number of cellular processes such as cell cycle progression and differentiation. There are at least 13 members in the S100 gene family, which are located as a cluster on chromosome 1q21; however, S100b is located at 21q22.3. The determination of S100B in serum levels may be used to monitor the extent of brain injury and malignant melanoma. S100b proteins may have a role in Neurite extension, proliferation of melanoma cells, stimulation of Ca2+ fluxes, inhibition of PKC-mediated phosphorylation, astrocytosis and axonal proliferation, and inhibition of microtubule assembly. Chromosomal rearrangements and altered expression of the S100b gene are implicated in several neurological, neoplastic, and other types of diseases, including Alzheimer's disease, Down's syndrome, epilepsy, amyotrophic lateral sclerosis, melanoma, and type I diabetes.

Actin is a muscle protein localized in the I band of the myofibrils; acting along with myosin, it is responsible for contraction and relaxation of muscle. Each actin protomer binds one molecule of ATP and has one high affinity site for either calcium or magnesium ions, as well as several low affinity sites. Actin exists as a monomer in low salt concentrations, but filaments form rapidly as salt concentration rises, with the consequent hydrolysis of ATP. It occurs in globular (G-actin) and fibrous (F-actin) forms. Actin is found in all eukaryotic cells (except for nematode sperm). Actin is one of the most highly-conserved proteins, differing by no more than 20% in species as diverse as algae and humans. Its other functions include cell motility, cell division and cytokinesis, vesicle and organelle movement, cell signaling, and the establishment and maintenance of cell junctions and cell shape.

Myelin Oligodendrocyte Glycoprotein is a membrane protein expressed on the oligodendrocyte cell surface and the outermost surface of myelin sheaths. Due to this localization, it is a prime target antigen that plays a role in immune-mediated demyelination. Myelin Oligodendrocyte Glycoprotein is involved in completion and maintenance of the myelin sheath and in cell-cell communication. MOG protein was found to differentially expressed in the dorsolateral prefrontal cortex and in the temporal lobe from patients with schizophrenia. MOG-specific antibody is crucial to the initiation of MOG-induced murine experimental autoimmune encephalomyelitis.

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.

Secreted frizzled-related protein 2 (SFRP2) belongs to the SFRP family which contains a cysteine-rich domain homologous to the putative Wnt-binding site of Frizzled proteins. SFRP2 function as soluble modulators of Wnt signaling. Methylation of SFRP2 is a possible marker for the existence of colorectal cancer.

SKP1 is a F-box enzyme which functions as a substrate recognition component of the SCF ubiquitin ligase complex which controls the ubiquitination of proteins involved in cell cycle progression, signal transduction and transcription. SKP1 binds to proteins containing an F-box motif, such as cyclin F, S-phase kinase-associated protein 2, and other regulatory proteins involved in ubiquitin dependent proteolysis. SKP1 takes part in the control of beta-catenin levels and the activity of beta-catenin dependent TCF transcription factors. SKP1 serves as an adapter that links the F-box protein to CUL1 in the SCF complex.

Ubiquitin-like-conjugating enzyme ATG10 (ATG10) is a 220 amino acid protein which localizes to the cytoplasm and has a role in autophagy, specifically acting as an E2-like enzyme providing Atg recognition sites during autophagosome synthesis. ATG10 functions as an E2-like enzyme which catalyzes the conjugation of ATG12 to ATG5, which is required for autophagy. In addition, ATG10 interacts with ATG12 in human embryonic kidney cells in the presence of ATG7. ATG10 probably serves as an ATG5-recognition molecule. Furthermore, ATG10 has a role in adenovirus-mediated cell lysis.

Osteoclasts are multinucleated cells that resorb bone and are essential for bone homeostasis. OSCAR plays crucial roles in the regulation of the innate and adaptive immune responses.Unlike the other LRC members, OSCAR expression is found specifically in preosteoclasts or mature osteoclasts. OSCAR is an important bone-specific regulator of osteoclast differentiation. Multiple alternative splicing transcript variants encodes different isoforms have been found for this gene.

ERP44 is an endoplasmic reticulum chaperone that takes part in thiol-dependent retention of the primary secretory pathway, forming mixed disulfides with substrate proteins through its conserved CRFS motif. ERP44 inhibits the calcium channel activity of ITPR1. ERP44 is involved in the control of oxidative protein folding in the endoplasmic reticulum.

FABP6 also called ileal fatty acid binding protein, is part of the small family of highly conserved, cytoplasmic proteins that bind long-chain fatty acids and other hydrophobic ligands. FABP6 cytosolic protein binds bile acid. FABP6 plays a role in fatty acid uptake, transport, and metabolism. FABP6 stimulates gastric acid and pepsinogen secretion. Seems to be able to bind to bile salts and bilirubins. FABP6 expression is restricted in the small intestine to the ileum where it is involved in the enterohepatic circulation of bile acids. Alternate transcription promoters generate 2 transcript variants, encoding a 128 aa and a 177 aa residue protein. Human FABP6 isoform 2 contains 128 amino acid residues and is acetylated on Ala2. FABP6 binds together fatty acids and bile acids and is directly involved in fatty acid transport and metabolism.

C17orf103 is a member of the GTLF3B family and is encoded by a gene which is located in human chromosome 17p11.2. BRCA1 and p53 are 2 main tumor suppressor genes which are linked to chromosome 17. Tumor suppressor p53 is necessary for maintenance of cellular genetic integrity by moderating cell fate through DNA repair versus cell death. C17orf103 is also related to neurofibromatosis, a disorder characterized by neural and epidermal lesions, and dysregulated Schwann cell growth.

CACYBP (calcyclin binding protein) participates in calcium-dependent ubiquitination and subsequent proteosomal degradation of target proteins. CACYBP acts as a molecular bridge in ubiquitin E3 complexes. CACYBP is involved in the ubiquitin-mediated degradation of beta-catenin.

Calreticulin 3 (CALR3) belongs to the calreticulin (CRT) family which consists of calcium binding chaperones that are localized to the endoplasmic reticulum or sarcoplasmic reticulum in eukaryotes. CALR3, which is expressed mainly in testis, takes part in protein-folding, oligomeric assembly and quality control in the ER. CALR3 plays an important role as a cancer-testis antigen due to its frequent expression in many cancers.

Chemokine (C-X-C motif) ligand 10 (CXCL10) is a small cytokine belonging to the CXC chemokine family. CXCL10 is secreted by several cell types. These cell types include monocytes, endothelial cells and fibroblasts. CXCL10 has been attributed to several roles, such as chemoattraction for monocytes and T cells, promotion of T cell adhesion to endothelial cells, antitumor activity, and inhibition of bone marrow colony formation and angiogenesis. The gene for CXCL10 is located on human chromosome 4 in a cluster among several other CXC chemokines. This chemokine elicits its effects by binding to the cell surface chemokine receptor CXCR3. The three-dimensional crystal structure of this chemokine has been determined under 3 different conditions to a resolution of up to 1.92A.

Phosphatidylinositol transfer protein alpha (PITPNA) is found in the cytoplasm, where it catalyzes the transfer of phosphatidylinositol (PI) and phosphatidylcholine (PC) between membranes. PITPNA belongs to a family of lipid-binding proteins which transfer molecules of phosphatidylinositol or phosphatidylcholine between membrane surfaces. PITPNA is implicated in phospholipase C signaling and in the production of phosphatidylinositol 3, 4, 5-trisphosphate (PIP3) by phosphoinositide-3-kinase.

Phosphatidylinositol transfer protein beta isoform (PITPNB) is found in the cytoplasm, where it catalyzes the transfer of phosphatidylinositol (PI) and phosphatidylcholine (PC) between membranes. PITPNB mobilizes PI from the endoplasmic reticulum and regulates its release from stored vesicles in the Golgi network. PITPNB is extensively expressed in various tissues.

BAT3 complex is a multiprotein complex which takes part in the post-translational delivery of tail-anchored (TA) membrane proteins to the endoplasmic reticulum membrane. Golgi To ER Traffic Protein 4 (GET4) is a part of the BAT3 complex. The complex functions by helping TA proteins (which contain a single C-terminal transmembrane region) which are captured by ASNA1/TRC40. BAT3 complex synthesizes membrane proteins, interacts with the transmembrane area of recently released TA proteins, and transfers them to ASNA1/TRC40 for targeting.

PSMG4 is a chaperone protein that enhances assembly of the 20S proteasome. PSMG4 cooperates with alpha and beta subunits of the 20S proteasome and with PSMG3 but disconnects when the POMP is recruited before the formation of half-proteasomes.

COMM Domain Containing (COMMD6) which is a part of the NF-kappa-B -inhibiting proteins, contains one COMM domain. COMMD6 down-regulates the activation of NF-kappa-B and inhibits TNF-induced NFKB1 activation.

Retinitis pigmentosa 9 (RP9) is assumed to be a target protein for the PIM1 kinase. The RP9 protein may have some roles in B-cell proliferation in association with PIM1. RP9 can be bound and phosphorylated by the protooncogene PIM1 product, a serine/threonine protein kinase. RP9 localizes in nuclear speckles containing the splicing factors, and has a part in pre-mRNA splicing. RP9 gene mutations result in autosomal dominant retinitis pigmentosa-9.

Mitochondrial methylglutaconyl-CoA hydratase (AUH) is involved in the amino acid degradation pathway by catalyzing the conversion of 3-methylglutaconyl-CoA to 3-hydroxy-3-methylglutaryl-CoA and water. AUH Human is expressed as a single mRNA species of 1.8 kb, and translated as a 40kDa precursor protein which is consequently processed to a 32kDa mature form. AUH has a very low enoyl-CoA hydratase activity. The AUH protein binds to the AU-rich element (ARE), which is a common element found in the 3' UTR of rapidly decaying mRNA such as c-fos, c-myc and granulocyte/ macrophage colony stimulating factor. AU-rich elements are involved in directing RNA to rapid degradation and deadenylation. In addition, AUH is homologous to enol-CoA hydratase, which is an enzyme involved in fatty acid degradation, and has been shown to have intrinsic hydratase enzymatic activity. AUH is therefore a bifunctional chimera between RNA binding and metabolic enzyme activity.

p38a/SAPK2 is a member of the MAP kinase family. MAP kinases act as an integration point for multiple biochemical signals, and are involved in a wide variety of cellular processes such as proliferation, differentiation, transcription regulation and development. This kinase is activated by various environmental stresses and proinflammatory cytokines. The activation requires its phosphorylation by MAP kinase kinases (MKKs), or its autophosphorylation triggered by the interaction of MAP3K7IP1/TAB1 protein with this kinase. The substrates of this kinase include transcription regulator ATF2, MEF2C, and MAX, cell cycle regulator CDC25B, and tumor suppressor p53, which suggest the roles of this kinase in stress related transcription and cell cycle regulation, as well as in genotoxic stress response. Four alternatively spliced transcript variants of this gene encoding distinct isoforms have been reported.

Reticulon 4 Receptor, also known as RTN4R, plays a role as a receptor for RTN4, OMG and MAG. RTN4R is a glycosylphosphoinositol (GPI)-anchored protein which is a part from the Nogo recptor family. RTN4R is expressed mainly in neurons and their axons and is regulates axonal regeneration and plasticity in the adult central nervous system. RTN4R is a potential drug target for treating various neurological cases such as spinal cord injury, CNS lesions, stroke and Alzheimer's disease.