A beta-spectrin isoform from Drosophila (beta H) is similar in size to vertebrate dystrophin.
A beta-spectrin isoform from Drosophila (beta H) is similar in size to vertebrate dystrophin.
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DOI：
10.1083/jcb.111.5.1849
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发表时间：
1990-11
期刊：
影响因子：
--
通讯作者：
Kiehart DP
中科院分区：
文献类型：
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作者：
Dubreuil RR;Byers TJ;Stewart CT;Kiehart DP
在许多细胞类型中，幽灵蛋白是膜骨架的主要组成部分，它们被认为对细胞形态和膜组织有贡献。血影蛋白亚型的多样性，特别是其β亚基的多样性，与细胞形状和膜结构的多样性有关。在这里，我们描述了果蝇的一个血影蛋白亚型，它由一个传统的α-血影蛋白亚基与一个新的高相对分子质量的β-亚基(430kD)复合而成，我们称之为β-H。天然的α-β-H分子以高亲和力结合肌动蛋白细丝，具有典型的血影蛋白形态，但它比大多数其他的血影蛋白亚型更长，并且包括两个被归因于β-H亚基的独特结构域的球状结构。βH由不同于之前描述的果蝇β-光谱蛋白亚基的基因编码，但与β-光谱蛋白以及脊椎动物的肌营养不良蛋白序列相似，后者是肌肉膜骨架的组成部分。在大小和序列相似性方面，dystrophin与新描述的β-血影蛋白亚型(βH)比与血影蛋白基因家族的其他成员(如α-血影蛋白和α-肌动蛋白)更相似。
Spectrins are a major component of the membrane skeleton in many cell types where they are thought to contribute to cell form and membrane organization. Diversity among spectrin isoforms, especially their beta subunits, is associated with diversity in cell shape and membrane architecture. Here we describe a spectrin isoform from Drosophila that consists of a conventional alpha spectrin subunit complexed with a novel high molecular weight beta subunit (430 kD) that we term beta H. The native alpha beta H molecule binds actin filaments with high affinity and has a typical spectrin morphology except that it is longer than most other spectrin isoforms and includes two knoblike structures that are attributed to a unique domain of the beta H subunit. Beta H is encoded by a different gene than the previously described Drosophila beta-spectrin subunit but shows sequence similarity to beta-spectrin as well as vertebrate dystrophin, a component of the membrane skeleton in muscle. By size and sequence similarity, dystrophin is more similar to this newly described beta-spectrin isoform (beta H) than to other members of the spectrin gene family such as alpha-spectrin and alpha- actinin.