Mutations in beta-spectrin disrupt axon outgrowth and sarcomere structure.
Mutations in beta-spectrin disrupt axon outgrowth and sarcomere structure.
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DOI：
10.1083/jcb.149.4.931
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发表时间：
2000-05-15
期刊：
影响因子：
--
通讯作者：
Jorgensen EM
中科院分区：
文献类型：
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作者：
Hammarlund M;Davis WS;Jorgensen EM
β-Spectrin是膜骨架的主要组成部分，膜骨架是大多数动物细胞的质膜结构。β-Spectrin和膜骨架已被提出用来稳定细胞膜，产生细胞极性，或定位特定的膜蛋白。我们证明秀丽线虫的β-Spectrin同源物是由unc-70基因编码的。UNC-70缺失突变体发育缓慢，成虫瘫痪、矮胖。然而，在UNC-70动物中，细胞膜的完整性没有受到损害，细胞的极性也没有受到影响。因此，β-SPECTIN对于细胞膜的完整性或细胞的极性并不是必需的。然而，细胞膜上的一部分过程需要β-Spectrin。在神经元中，β-SPECTIN的丢失会导致轴突异常生长。在肌肉中，β-SPECTIN的丢失导致肌丝格子的破坏，致密小体的中断，以及肌浆网的减少或丢失。这些缺陷与β-SPECTIN在细胞膜上锚定蛋白质的功能一致。
β-Spectrin is a major component of the membrane skeleton, a structure found at the plasma membrane of most animal cells. β-Spectrin and the membrane skeleton have been proposed to stabilize cell membranes, generate cell polarity, or localize specific membrane proteins. We demonstrate that the Caenorhabditis elegans homologue of β-spectrin is encoded by the unc-70 gene. unc-70 null mutants develop slowly, and the adults are paralyzed and dumpy. However, the membrane integrity is not impaired in unc-70 animals, nor is cell polarity affected. Thus, β-spectrin is not essential for general membrane integrity or for cell polarity. However, β-spectrin is required for a subset of processes at cell membranes. In neurons, the loss of β-spectrin leads to abnormal axon outgrowth. In muscles, a loss of β-spectrin leads to disorganization of the myofilament lattice, discontinuities in the dense bodies, and a reduction or loss of the sarcoplasmic reticulum. These defects are consistent with β-spectrin function in anchoring proteins at cell membranes.