ELISA

Betaglycan also known as Transforming growth factor beta receptor III (TGFBR3), is a cell-surface chondroitin sulfate / heparan sulfate proteoglycan >300 kDa in molecular weight. Betaglycan binds to various members of the TGF-beta superfamily of ligands via its core protein, and bFGF via its heparan sulfate chains. It is not involved directly in TGF-beta signal transduction but by binding to various member of the TGF-beta superfamily at the cell surface it acts as a reservoir of ligand for TGF-beta receptors. By cDNA array and immunohistochemistry analyses, it is found that TGFBR3 expression is lost in most breast cancers examined in association with loss of heterozygosity of the TGFBR3 locus. TGFBR3 expression decreased during breast cancer progression, and low levels predicted decreased recurrence-free survival in patients. Loss of TGFBR3 through allelic imbalance is a frequent genetic event during breast cancer development that increases metastatic potential. Also, TGFBR3 can locali

Lysyl oxidase homolog 2 is an enzyme that in humans is encoded by the LOXL2 gene. This gene encodes a member of the lysyl oxidase gene family. The prototypic member of the family is essential to the biogenesis of connective tissue, encoding an extracellular copper-dependent amine oxidase that catalyses the first step in the formation of crosslinks in collagens and elastin. A highly conserved amino acid sequence at the C-terminus end appears to be sufficient for amine oxidase activity, suggesting that each family member may retain this function. The N-terminus is poorly conserved and may impart additional roles in developmental regulation, senescence, tumor suppression, cell growth control, and chemotaxis to each member of the family. LOXL2 can also crosslink collagen type IV and hence influence the sprouting of new blood vessels.

Antithrombin III is the most important inhibitor of thrombin and other coagulation proteinases. It belongs to the serine proteinase inhibitor (serpin) superfamily of inhibitors and structurally related proteins, which contain reactive centers that have evolved to attract and entrap certain proteinases. Inherited antithrombin III deficiency (AT3D) is a risk factor for the early development of venous thromboembolism (THPH7). Antithrombin III regulates clot formation both by inhibiting thrombin activity directly and by interfering with earlier stages of the clotting cascade. By in situ hybridization and quantitative analysis of DNA dosage in carriers of chromosome 1 deletions, AT3 is mapped to 1q23-q25. The AT3 gene has 7 exons. It contains 9 complete and 1 partial repetitive ALU sequence elements, which occur in the introns of the gene at a higher frequency (about 22% of the intron sequence) than in the genome as a whole (about 5%).

Epiregulin (EPR) is a protein that in humans is encoded by the EREG gene. It is a member of the epidermal growth factor family. Epiregulin can function as a ligand of epidermal growth factor receptor (EGFR), as well as a ligand of most members of the ERBB (v-erb-b2 oncogene homolog) family of tyrosine-kinase receptors. The secondary structure at the C-terminus epiregulin is different from other epidermal growth factor family ligands because of the lack of hydrogen bonds. The structural difference at the C-terminus may provide an explanation for the reduced binding affinity of epiregulin to the ERBB receptors.

Epiregulin (EPR) is a protein that in humans is encoded by the EREG gene. It is a member of the epidermal growth factor family. Epiregulin can function as a ligand of epidermal growth factor receptor (EGFR), as well as a ligand of most members of the ERBB (v-erb-b2 oncogene homolog) family of tyrosine-kinase receptors. The secondary structure at the C-terminus epiregulin is different from other epidermal growth factor family ligands because of the lack of hydrogen bonds. The structural difference at the C-terminus may provide an explanation for the reduced binding affinity of epiregulin to the ERBB receptors.

Receptor tyrosine-protein kinase erbB-3, also known as HER3 (human epidermal growth factor receptor 3), is a membrane bound protein that in humans is encoded by the ERBB3 gene. ErbB3 has been shown to bind the ligands heregulin and NRG-2. Ligand binding causes a change in conformation that allows for dimerization, phosphorylation, and activation of signal transduction. ErbB3 can heterodimerize with any of the other three ErbB family members. The theoretical ErbB3 homodimer would be non-functional because the kinase-impaired protein requires transphosporylation by its binding partner to be active. Unlike the other ErbB receptor tyrosine kinase family members which are activated through autophosphorylation upon ligand binding, ErbB3 is found to be kinase impaired, having only 1/1000th the autophosphorylation activity of EGFR and no ability to phosphorylate other proteins. Therefore, ErbB3 must act as anallosteric activator.

Complement factor H (CFH), originally known as beta-1H globulin, is a serum glycoprotein that regulates the function of the alternative complement pathway in fluid phase and on cellular surfaces. It binds to C3b, accelerates the decay of the alternative pathway convertase C3bBb, and also acts as a cofactor for complement factor I, another C3b inhibitor. The CFH gene is located on chromosome 1q32-q32.1 within a cluster of genes encoding the regulatory complement components of the activation of C3 (RCA for 'regulators of complement activation'). This gene cluster includes decay-accelerating factor (DAF), C4-binding protein (C4BPA and C4BPB), and the factor H-related genes CFHR1, CFHR2, CFHR3, CFHR4, and CFHR5, among others. The gene family has arisen by multiple duplication events.

Complement factor H (CFH), originally known as beta-1H globulin, is a serum glycoprotein that regulates the function of the alternative complement pathway in fluid phase and on cellular surfaces. It binds to C3b, accelerates the decay of the alternative pathway convertase C3bBb, and also acts as a cofactor for complement factor I, another C3b inhibitor. The CFH gene is located on chromosome 1q32-q32.1 within a cluster of genes encoding the regulatory complement components of the activation of C3 (RCA for 'regulators of complement activation'). This gene cluster includes decay-accelerating factor (DAF), C4-binding protein (C4BPA and C4BPB), and the factor H-related genes CFHR1, CFHR2, CFHR3, CFHR4, and CFHR5, among others. The gene family has arisen by multiple duplication events.

Chordin is a key developmental protein that dorsalizes early vertebrate embryonic tissues by binding to ventralizing TGF-beta-like bone morphogenetic proteins (BMPs) and sequestering them in latent complexes. In mice, Chordin is expressed in the node but not in the anterior visceral endoderm. It has been found to be required for forebrain development. In developing mice that are deficient in both chordin and noggin, the head is nearly absent. This is significant because when only noggin is deficient there are mild defects but the head still forms. Chordin is also involved in avian gastrulation. It is expressed in the anterior cells of Koller's sickle, which form the anterior cells of the primitive streak, a key structure through which gastrulation occurs.