Collagen type XIV degradation by MMP9,13

Collagen type XIV is a member of the fibril-associated collagens with interrupted triple helices (FACIT) family, expressed in most mesenchymal tissues. The non-collagenous domain at the N-terminus of collagen XIV is extremely large, nearly 80% of the entire polypeptide. This domain is composed of eight fibronectin type III repeats, two von Willebrand factor A-like (vWFA) domains and one non-collagenous domain 4 (NC4 domain) related to collagen type IX. Collagen XIV is expressed in most mesenchymal tissues where it appears to interact with collagen type VI, glycosaminoglycans, proteoglycans and matrix receptors (Brown et al. 1993, Imhof & Trueb 1998). It has been implicated as a regulator of fibrillogenesis. Collagen type XIV deficient mice have a grossly normal phenotype but their skin has altered mechanical properties. Tendons were seen to be enlarged at postnatal day 4 though mature tendons appeared normal. Tendons from postnatal day 7 KO mice had reduced strength but by 60 days were comparable with wild-type (Ansorge et al. 2009). Adult Col14a1 mice have defects in ventricular morphogenesis (Tao et al. 2012).<br><br>Collagen type XIV is degraded by MMP9 (Sires et al. 1995) and MMP13 (Knauper et al. 1997).

胶原XIV是纤维相关胶原中断三螺旋（FACIT）家族的一员，广泛表达于大多数间充质组织中。胶原XIV的N端非胶原结构域极为庞大，几乎占整个多肽的80%。该结构域由八个纤连蛋白III型重复序列、两个冯·维勒布兰特因子A样（vWFA）结构域以及一个与胶原IX相关的非胶原结构域4（NC4结构域）组成。胶原XIV在大多数间充质组织中表达，似乎与胶原VI、氨基糖聚糖、蛋白聚糖和基质受体相互作用（Brown等，1993；Imhof & Trueb，1998）。它已被认为是一种原纤维生成调节因子。胶原XIV缺乏小鼠表现出大致正常的表型，但皮肤机械特性发生改变。出生后第4天观察到跟腱增大，尽管成熟的跟腱外观正常。出生后第7天KO小鼠的跟腱强度降低，但到60天时与野生型小鼠相当（Ansorge等，2009）。成年Col14a1小鼠在心室形态发生方面存在缺陷（Tao等，2012）。胶原XIV被MMP9（Sires等，1995）和MMP13（Knauper等，1997）降解。