Nidogen is nonessential and not required for normal type IV collagen localization in Caenorhabditis elegans
Nidogen is nonessential and not required for normal type IV collagen localization in Caenorhabditis elegans
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DOI：
10.1091/mbc.11.11.3911
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发表时间：
2000-11-01
影响因子：
3.3
通讯作者：
Kramer, JM
中科院分区：
文献类型：
--
作者：
Kang, SH;Kramer, JM
巢蛋白（巢蛋白）可与IV型胶原和层粘连蛋白形成三元复合物，并被认为在基底膜组装中起关键作用。我们发现，秀丽隐杆线虫巢同源nid-1产生三种亚型，不同的杆域内皮生长因子重复序列的数量，并在发展过程中差异表达。NID-1出现在与肌肉细胞相关的胚胎形态发生的开始，随后在咽、肠和性腺原基上积累。在幼虫和成虫中，NID-1在大多数基底膜中被检测到，但在神经环和发育中的性腺周围积聚最强烈。NID-1集中在致密体下，肌肉象限的边缘，以及在肌肉下运行的亚外侧神经上。分离出两个nid-1缺失：cg 119是分子空，而cg 118产生缺失G2胶原TV结合结构域的截短的NID-1。这两种缺失都不会引起明显的异常表型，除了生育力轻度降低。截短的cg 118 NID-1显示野生型定位，表明G2结构域不是巢蛋白组装所必需的。这两个nid-1突变体组装IV型胶原蛋白在一个完全野生型的模式，表明巢蛋白是不必要的IV型胶原蛋白组装成基底膜。
Nidogen (entactin) can form a ternary complex with type IV collagen and laminin and is thought to play a critical role in basement membrane assembly. We show that the Caenorhabditis elegans nidogen homologue nid-1 generates three isoforms that differ in numbers of rod domain endothelial growth factor repeats and are differentially expressed during development. NID-1 appears at the start of embryonic morphogenesis associated with muscle cells and subsequently accumulates on pharyngeal, intestinal, and gonad primordia. In larvae and adults NID-1 is detected in most basement membranes but accumulates most strongly around the nerve ring and developing gonad. NID-1 is concentrated under dense bodies, at the edges of muscle quadrants, and on the sublateral nerves that run under muscles. Two deletions in nid-1 were isolated: cg119 is a molecular null, whereas cg118 produces truncated NID-1 missing the G2 collagen TV binding domain. Neither deletion causes overt abnormal phenotypes, except for mildly reduced fecundity. Truncated cg118 NID-1 shows wild-type localization, demonstrating that the G2 domain is not necessary for nidogen assembly. Both nid-1 mutants assemble type IV collagen in a completely wild-type pattern, demonstrating that nidogen is not essential for type IV collagen assembly into basement membranes.