Collagen IV Alpha4 (COL4A4) Antibody – Rabbit

This gene encodes one of the six subunits of type IV collagen, the major structural component of basement membranes. This particular collagen IV subunit, however, is only found in a subset of basement membranes. Like the other members of the type IV collagen gene family, this gene is organized in a head-to-head conformation with another type IV collagen gene so that each gene pair shares a common promoter. Mutations in this gene are associated with type II autosomal recessive Alport syndrome (hereditary glomerulonephropathy) and with familial benign hematuria (thin basement membrane disease). Two transcripts, differing only in their transcription start sites, have been identified for this gene and, as is common for collagen genes, multiple polyadenylation sites are found in the 3' UTR. [provided by RefSeq, Jul 2008]

COL4A4: Type IV collagen is the major structural component of glomerular basement membranes (GBM), forming a 'chicken-wire' meshwork together with laminins, proteoglycans and entactin/nidogen. Defects in COL4A4 are a cause of Alport syndrome autosomal recessive (APSAR). APSAR is characterized by progressive glomerulonephritis, glomerular basement membrane defects, renal failure, sensorineural deafness and specific eye abnormalities (lenticonous and macular flecks). The disorder shows considerable heterogeneity in that families differ in the age of end-stage renal disease and the occurrence of deafness. Defects in COL4A4 are a cause of benign familial hematuria (BFH); also known as thin basement membrane nephropathy. BFH is characterized by persistent hematuria, an electron microscopically detectable thin glomerular basement membrane (GBM) and an autosomal dominant mode of inheritance. Renal function remains normal. In children, differentiation between BFH and AS can be difficult, because both disorders are manifested by persistent hematuria and thin GBM at that age. Belongs to the type IV collagen family.

Protein type: Secreted, signal peptide; Secreted

Chromosomal Location of Human Ortholog: 2q35-q37

Cellular Component: endoplasmic reticulum lumen; collagen type IV; extracellular region; basal lamina

Molecular Function: extracellular matrix structural constituent

Biological Process: axon guidance; extracellular matrix disassembly; collagen catabolic process; extracellular matrix organization and biogenesis; glomerular basement membrane development

Disease: Alport Syndrome, Autosomal Recessive