Collagen IV (Coliv or Col4) is a type of collagen found mainly in the basal lamina. Collagen IV C4 domains in C-terminus are not removed in the post-translational process, and fiber connects head-to-head, rather than in parallel. Also, collagen IV has no ordinary glycine in any third residue required for strict helical collagen. This makes the overall arrangement more careless with tangles. Both of these features cause collagen to form in sheets, the form of a basal lamina. Collagen IV is a more common use, compared to the longer term "collagen type-IV" terminology. Collagen IV is present in all metazoan phyla.
There are six human genes associated with it:
- COL4A1, COL4A2, COL4A3, COL4A4, COL4A5, COL4A6
Video Type IV collagen
Clinical interests
The alpha-3 subunit (COL4A3) of collagen IV is considered an antigen involved in Goodpasture disease, in which the immune system attacks the basal membrane of the glomeruli and the alveoli at the antigenic site of the alpha-3 subunit becomes untouched due to environmental exposure.
Goodpasture disease presents with nephritic syndrome and haemoptysis. The microscopic evaluation of the biopsied kidney tissue will reveal a linear deposit of Immunoglobulin G by immunofluorescence. This is classically a young adult male.
Mutations in genes encoding collagen IV cause Alport syndrome. This will lead to thinning and separation of the glomerular basement membrane. These will be present as isolated hematuria, sensorineural hearing loss, and genetically inherited and ocular disorders, usually in an X-linked manner, although there is a rare autosomal form.
Liver fibrosis and cirrhosis are associated with deposition of collagen IV in the liver. Serum Collagen IV concentrations correlated with levels of IV collagen liver tissue in subjects with alcoholic liver disease and hepatitis C and fell after successful therapy.
Increased glomerular deposition and mesangial collagen IV occur in diabetic nephropathy and elevated urinary levels are associated with rates of renal injury.
Maps Type IV collagen
References
External links
- Type IV collagen at US National Library of Medicine Subject Medical Headings (MeSH)
Source of the article : Wikipedia
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