Cleaved collagen type XI fibril Collagen type XI fibril Collagen type XI degradation by MMP1,2,3,9 Authored: Jupe, S, 2011-07-12 Collagen type XI has 3 types of alpha chain. The alpha1(XI) and alpha2(XI) chains are distinct gene products unique to collagen XI, while alpha3(XI) is a hyperglycosylated form of the alpha1 chain for collagen II (Burgeson & Hollister 1979, Morris & Bächinger 1987). Collagen type XI is a fibril-forming collagen found in conjunction with collagens type II and IX in cartilage fibrils (Miller & Gay 1987, Mendler et al. 1989). It is thought to be the structural equivalent of collagen V in connective tissue collagen fibrils. The formation of cartilage collagen fibrils requires collagen XI, suggesting a regulatory function (Li et al. 1995, Wu & Eyre 1995). <br><br>Mutations in COL11A1 result in fibrochondrogenesis, a severe, autosomal-recessive, short-limbed skeletal dysplasia (Tompson et al. 2010). Variations in COL11A1, COL11A2 and COL2A1 are associated with the inherited chondrodysplasias Marshall and Stickler syndromes (Annunen et al. 1999).<br><br>Collagen type XI is degraded by MMP1 (Eyre et al. 1984), MMP2 (Yu et al. 1990, Smith et al. 1991, Brown et al. 1996), MMP3 (Wu et al. 1991) and MMP9 (Hirose et al. 1992, Pormotabbed et al. 1994). EC Number: 3.4.21 Edited: Jupe, S, 2012-11-12 Pubmed10486316 Pubmed1317454 Pubmed1851245 Pubmed2005102 Pubmed21035103 Pubmed2173606 Pubmed2463256 Pubmed3112157 Pubmed3306286 Pubmed465027 Pubmed6322761 Pubmed7642541 Pubmed7859283 Pubmed8305481 Pubmed8670744 Reactome Database ID Release 431564179 Reactome, http://www.reactome.org ReactomeREACT_150259 Reviewed: Sorsa, Timo, 2012-10-08