Fibrinogen (TNXB) Native Protein

This gene encodes a member of the tenascin family of extracellular matrix glycoproteins. The tenascins have anti-adhesive effects, as opposed to fibronectin which is adhesive. This protein is thought to function in matrix maturation during wound healing, and its deficiency has been associated with the connective tissue disorder Ehlers-Danlos syndrome. This gene localizes to the major histocompatibility complex (MHC) class III region on chromosome 6. It is one of four genes in this cluster which have been duplicated. The duplicated copy of this gene is incomplete and is a pseudogene which is transcribed but does not encode a protein. The structure of this gene is unusual in that it overlaps the CREBL1 and CYP21A2 genes at its 5' and 3' ends, respectively. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]

TNXB: Appears to mediate interactions between cells and the extracellular matrix. Substrate-adhesion molecule that appears to inhibit cell migration. Accelerates collagen fibril formation. May play a role in supporting the growth of epithelial tumors. Defects in TNXB are the cause of tenascin-X deficiency (TNXD). TNXD leads to an Ehlers-Danlos-like syndrome characterized by hyperextensible skin, hypermobile joints, and tissue fragility. Tenascin-X-deficient patients, however, lack atrophic scars, a major diagnostic criteria for classic Ehlers- Danlos. Delayed wound healing, which is also common in classic EDS, is only present in a subset of patients. Belongs to the tenascin family. 3 isoforms of the human protein are produced by alternative splicing.

Protein type: Extracellular matrix; Secreted; Motility/polarity/chemotaxis; Secreted, signal peptide

Chromosomal Location of Human Ortholog: 6p21.3

Cellular Component: extracellular matrix; extracellular space; proteinaceous extracellular matrix; fibrillar collagen; intracellular

Molecular Function: integrin binding; collagen binding; heparin binding

Biological Process: elastic fiber assembly; cell-cell adhesion; collagen fibril organization; triacylglycerol metabolic process; collagen metabolic process; cell-matrix adhesion; regulation of JNK activity; fibril organization and biogenesis; cell adhesion; fatty acid metabolic process; actin cytoskeleton organization and biogenesis

Disease: Ehlers-danlos-like Syndrome Due To Tenascin-x Deficiency; Vesicoureteral Reflux 8