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Mannose-6-Phosphate Receptor (M6PR) belongs to the P-type lectin family. P-type lectins play a vital role in lysosome function through the specific transport of mannose-6-phosphate-containing acid hydrolases from the Golgi complex to lysosomes. The M6PR protein functions as a homodimer and needs divalent cations for ligand binding. Lysosomal enzymes carrying phosphomannosyl residues bind specifically to mannose-6-phosphate receptors in the Golgi apparatus and the ensuing receptor-ligand complex is transferred to an acidic prelyosomal compartment where the low pH mediates the dissociation of the complex.

COPZ1 is a member of the adaptor complexes small subunit family. Coatomer is an oligomeric complex which contains as a minimum the alpha, beta, beta', gamma, delta, epsilon and zeta subunits. The zeta subunit has a part in regulating the coat assembly and, therefore, the rate of biosynthetic protein transport due to its association-dissociation properties with the coatomer complex.

Chemokine (C-C motif) ligand 2 (CCL2) is a small cytokine belongs to the CC chemokine family which is also known as monocyte chemotactic protein-1 (MCP-1). MCP 1 is found at the site of tooth eruption and bone degradation. In the bone, CCL2 is expressed by mature osteoclasts. CCL2 recruits immune cells, such as monocytes, to sites of tissue injury and infection. MCP 1is produced as a protein precursor containing signal peptide of 23 amino acids and a mature peptide of 76 amino acids. As with many other CC chemokines, CCL2 is located on chromosome 17 in humans. The cell surface receptors that bind CCL2 are CCR2 and CCR5.

Type IV collagen is a major structural component of basement membranes. It is a multimeric protein composed of 3 alpha subunits, which are encoded by 6 different genes, alpha 1 through alpha 6. Each of these alpha subunits can form a triple helix structure with 2 other subunits to form type IV collagen. The Goodpasture syndrome is a condition in which autoantibodies bind to the collagen molecules in the basement membranes of alveoli and glomeruli. The epitopes that elicit these autoantibodies are restricted basically to the non-collagenous C-terminal domain of the protein. There are numerous alternative transcripts that appear to be unique to the human COL4A3 and alternative splicing is limited to the six exons that encode this C-terminal domain. COL4A3 is also linked to an autosomal recessive form of Alport syndrome. The mutations contributing to the Alport syndrome are also situated within the exons that encode this C-terminal region. COL4A3 is organized in a head-to-head conformation with another type IV collagen gene so that each gene pair shares a common promoter. Several exons of COL4A3 are interspersed with exons of an uncharacterized gene which is on the opposite strand.

Galectin-4 is a member of the subfamily of galectins composed of two carbohydrate recognition domains having similar peptide chains. The galectins are a family of beta-galactoside-binding proteins having a role in modulating cell-cell and cell-matrix interactions, which inhibits chronic inflammations, GVHD, and allergic responses. LGALS4 expression is limited to small intestine, colon, and rectum, and it is underexpressed in colorectal cancer. LGALS4 binds as an endogenous ligand to glycosphingolipids having 3-O-sulfated Gal residues and bind as well to cholesterol-3-sulfate. LGALS4 takes part in cell adhesion. LGALS4 plays a role in crosslinking the lateral cell membranes of the surface-lining epithelial cells, thus supporting epithelial integrity against mechanical stress exerted by the bowel lume. LGALS4 is in charge of intestinal inflammation via selective regulation of peripheral and mucosal T-cell cell cycle, in addition to cell death by apoptosis of T-cells by a pathway independent of the activation of caspases. LGALS4 blockade decreases TNF-alpha inhibitor induced T-cell death. LGALS4 decreases pro-inflammatory cytokine secretion including IL-6 & IL-17.

Crk-like protein (CRKL) is a protein kinase containing SH2 and SH3 (src homology) domains which activates the RAS and JUN kinase signaling pathways and transforms fibroblasts in a RAS-dependent manner. CRKL is a substitute of the BCR-ABL tyrosine kinase, it also has a role in fibroblast transformation by BCR-ABL, and has oncogenic potential.

MGP is vital for the regulation of calcification in the extracellular matrix, particularly in cartilage and arteries. The K-dependent vitamin MGP has five to six residues of Gla, a Ca2+ binding amino acid crucial for vitamin K-dependent gamma carboxylase for its formation. MGP is formed by COOH-terminal processing by carboxypeptidase B-like enzymatic activity and localized in the human bone.

SAP18 is a component of the histone deacetylase complex which has a significant role in the regulation of eukaryotic gene expression. SAP18 directly interacts with SIN3 and enhances SIN3-mediated transcriptional repression once bound to the promoter. SAP18 plays an important part in gene-specific recruitment of the HDAC complex by a number of transcription factors including Gli, GAGA, and Bicoid. Histone acetylation is significant in the regulation of eukaryotic gene expression. Histone acetylation and deacetylation is catalyzed by multisubunit complexes. SAP18 is a component of the histone deacetylase complex, which includes SIN3, SAP30, HDAC1, HDAC2, RbAp46, RbAp48, and other polypeptides. SAP18 is a component of a splicing-dependent multiprotein EJC (exon junction complex) placed at splice junction on mRNAs.

Mammalian mitochondrial ribosomal proteins are encoded by nuclear genes and aid in protein synthesis within the mitochondrion. Mitochondrial ribosomes (mitoribosomes) comprised of a small 28S subunit and a large 39S subunit. Among different species, the proteins comprising the mitoribosome vary greatly in sequence, and sometimes in biochemical properties, thus preventing simple recognition by sequence homology. Mitochondrial Ribosomal Protein L2 (MRPL2) is a 39S subunit protein which is a member of the EcoL2 ribosomal protein family.

Cytohesin-interacting protein, also known as CYTIP contains 2 leucine zipper domains as well as a putative C-terminal nuclear targeting signal. However, CYTIP does not contain any hydrophobic regions. In addition, CYTIP is expressed weakly in resting NK and T cells. It also modulates the activation of ARF genes by CYTH1.

Dynactin 6, also known as DCTN6 is a member of the dynactin subunits 5/6 family. DCTN6 includes an RGD (Arg-Gly-Asp) motif in the N-terminal region, which confers adhesive properties to macromolecular proteins such as fibronectin. DCTN6 has a high degree of sequence resemblance with the mouse homolog, which has been found to participate in mitochondrial biogenesis. Moreover, the precise biological function of DCTN6 is unknown.

MAX Dimerization Protein 3 (MXD3) belongs to the Myc superfamily of basic helix-loop-helix leucine zipper transcriptional regulators. MXD3 forms a heterodimer with the cofactor MAX that connects specific E-box DNA motifs in the promoters of target genes and regulates their transcription. Disturbance of the MAX-MXD3 complex is correlated with uncontrolled cell proliferation and tumorigenesis. Transcript variants of MXD3 encoding different isoforms have been described.

ANXA2 is part of the annexin family and is involved in the regulation of cellular growth and in signal transduction pathways. ANXA2 protein functions as an autocrine factor which increases osteoclast formation and bone resorption. ANXA2 is associated with sickle cell osteonecrosis. Reduced ANXA2 expression is associated with osteosarcoma metastases. ANXA2 is part of the putative cell surface vitamin D binding protein binding site complex and functions to mediate the chemotactic cofactor effect. ANXA2 is involved in dysferlin deficiency and in muscular dystrophies. Human colon adenocarcinoma cell differentiation is related with an up-regulation of ANXA2.

Recombinant Human Sonic Hedgehog is part of a small group of secreted proteins that are vital for development in both vertebrates and invertebrates. 3 mammalian hedgehog genes (sonic, desert, Indian) share about 60% homology. The Human Sonic Hedgehog is 99% homologous to the mouse gene. Sonic HedgeHog is a protein that is vital in guding the early embryo. It has been associated as the major inductive signal in patterning of the ventral neural tube, the anterior-posterior limb axis, and the ventral somites. Sonic HedgeHog binds to the patched receptor, which functions in association with smoothened, to activate the transcription of target genes. In the absence of sonic HedgeHog, patched receptor represses the constitutive signaling activity of smoothened. Sonic HedgeHog also regulates another factor, the gli oncogene. Sonic HedgeHog intercellular signal is essential for a various patterning events during development: signal produced by the notochord that induces ventral cell fate in the

Signal-Regulatory Protein Gamma (SIRPG) belongs to the signal-regulatory protein (SIRP) family whose members are receptor-type transmembrane glycoproteins which negatively regulate the receptor tyrosine kinase-coupled signaling processes. SIRPG is also a part of the immunoglobulin superfamily.

ASF1 Anti-Silencing Function 1 Homolog B (ASF1B) belongs to the H3/H4 family of histone chaperone proteins and is similar to the anti-silencing function-1 protein in yeast. ASF1B is the substrate of the tousled-like kinase family of cell cycle-regulated kinases, and may have a crucial role in modulating the nucleosome structure of chromatin by guaranteeing a regular supply of histones at sites of nucleosome assembly. ASF1B cooperates with CAF-1 (chromatin assembly factor 1) to stimulate replication-dependent chromatin assembly. ASF1B is highly expressed in the testis and at lower levels in colon, small intestine and thymus. ASF1B is necessary for spermatogenesis.

Autophagy Related 3 (ATG3) is a conjugating enzyme essential for the cytoplasm to vacuole transport (Cvt), autophagy, and mitochondrial homeostasis. ATG3 is localizes to the cytoplasm and is expressed in tissues with predominant levels found in kidney, placenta, liver, heart and skeletal muscle. ATG3 catalyzes a reaction which is necessary for autophagy. That reaction is the formation of the Atg8-phosphatidylethanolamine (ATG-PE) conjugate.

Chemokine (C-X-C motif) ligand 5 (CXCL5) is a small cytokine belonging to the CXC chemokine family that is also known as epithelial-derived neutrophil-activating peptide 78 (ENA-78). It is produced following stimulation of cells with the inflammatory cytokines interleukin-1 or tumor necrosis factor-alpha. Expression of CXCL5 has also been observed in eosinophils. This chemokine stimulates the chemotaxis of neutrophils possesses angiogenic properties. It elicits these effects by interacting with the cell surface chemokine receptor CXCR2. The gene for CXCL5 is encoded on four exons and is located on human chromosome 4 amongst several other CXC chemokine genes. CXCL5 has been implicated in connective tissue remodelling.

Single-Stranded DNA Binding Protein 1 (SSBP) participates in mitochondrial biogenesis. SSBP binds preferentially and cooperatively to ss-DNA. The SSBP protein is involved in mitochondrial DNA replication and associates with mitochondrial DNA.

Epiregulin is part of the EGF family. Epiregulin functions as a ligand of EGFR, as well as a ligand of most members of the ERBB (v-erb-b2 oncogene homolog) family of tyrosine-kinase receptors.Epiregulin is expressed mostly in the placenta and peripheral blood leukocytes and in specific carcinomas of the bladder, lung, kidney and colon. Epiregulin stimulates the proliferation of keratinocytes, hepatocytes, fibroblasts and vascular smooth muscle cells. Epiregulin inhibits the growth of several tumor-derived epithelial cell lines. Human Epiregulin is initially synthesized as a glycosylated 19.0 kDa transmembrane precursor protein, which is processed by proteolytic cleavage to produce a 6.0 kDa mature secreted sequence.

Endothelial cell-specific molecule 1 (ESM1) is a proteoglycan secreted by endothelial cells (mostly in the human lung and kidney tissues) and its mRNA expression is regulated by inflammatory cytokines. ESM1 has potent implications in lung endothelial cell-leukocyte interactions. In addition, ESM1 expression is detected in various epithelia and in adipocytes. ESM1 is involved in angiogenesis and it also promotes angiogenic sprouting. ESM1 expression is upregulated by TNF alpha, IL1 beta, or lipopolysaccharide and downregulated by IFN gamma. Genetically engineered cells overexpressing ESM1 induce tumor formation, implying that ESM1 might be involved in the pathophysiology of tumor growth in vivo.

SUMO1 is a protein that belongs to the SUMO (small ubiquitin-like modifier) protein family. SUMO1 functions in a manner similar to ubiquitin in that it is bound to target proteins as part of a post-translational modification system. Still, unlike ubiquitin which targets proteins for degradation, SUMO1 is involved in a variety of cellular processes, for example nuclear transport, transcriptional regulation, apoptosis, and protein stability. SUMO1 is not active until the last four amino acids of the carboxy-terminus are cleaved off.

Small Ubiquitin-like Modifiers (SUMOs) are a family of small, related proteins that can be enzymatically attached to a target protein by a post-translational modification process termed sumoylation. Unlike ubiquitination, which targets proteins for degradation, sumoylation participates in a number of cellular processes, such as nuclear transport, transcriptional regulation, apoptosis, and protein stability. All SUMO proteins share the conserved ubiquitin domain and the C-terminal diglycine cleavage/attachment site. Human SUMO2, also known as Sentrin2 and SMT3B is synthesized as a 95 amino acid (aa), 11 kDa propeptide that contains a two aa C-terminal prosegment, and an 18 aa N-terminal protein interacting region (aa 33 -50). Following prosegment cleavage, the C-terminal glycine is enzymatically attached to a lysine on a target protein. Human SUMO2 shares 100% sequence identity to SUMO-2 from mouse. SUMO2 also has very high sequence homology to SUMO3 and SUMO4, 86 % and 85%, respectively. SUMO2 shares only 44% sequence identity to SUMO1.

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.