Myosin and paramyosin are organized about a newly identified core structure.
Myosin and paramyosin are organized about a newly identified core structure.
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DOI：
10.1083/jcb.100.3.904
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发表时间：
1985-03
期刊：
影响因子：
--
通讯作者：
Berliner GC
中科院分区：
文献类型：
--
作者：
Epstein HF;Miller DM 3rd;Ortiz I;Berliner GC
肌球蛋白同种型A和B分别不同地定位于秀丽隐杆线虫体壁肌细胞中粗丝的中心和极区（米勒，D. M. III，I. Ortiz，G. C. Berliner和H. F. Epstein，1983，Cell，34：477-490）。KCl-解离丝的生化和电子显微镜研究表明，肌球蛋白亚型占据表面域，副肌球蛋白构成中间域，和一个新发现的核心结构存在。粗纤维的直径从中心的33.4 nm到末端附近的14.0 nm变化显著。后一个值与核结构的15.2 nm直径相当。内部密度的细丝核心出现实心中间和中空的两极。粗丝结构分化为具有特定稳定性的亚结构的超分子结构域，表明粗丝组装的顺序模式。在该模型中，两种肌球蛋白亚型在组装中具有不同的作用。肌球蛋白的行为，包括成核组装和细丝长度的确定，取决于副肌球蛋白和核心结构以及它们的内在分子特性。
Myosin isoforms A and B are differentially localized to the central and polar regions, respectively, of thick filaments in body wall muscle cells of Caenorhabditis elegans (Miller, D. M. III, I. Ortiz, G. C. Berliner, and H. F. Epstein, 1983, Cell, 34:477-490). Biochemical and electron microscope studies of KCl-dissociated filaments show that the myosin isoforms occupy a surface domain, paramyosin constitutes an intermediate domain, and a newly identified core structure exists. The diameters of the thick filaments vary significantly from 33.4 nm centrally to 14.0 nm near the ends. The latter value is comparable to the 15.2 nm diameter of the core structures. The internal density of the filament core appears solid medially and hollow at the poles. The differentiation of thick filament structure into supramolecular domains possessing specific substructures of characteristic stabilities suggests a sequential mode for thick filament assembly. In this model, the two myosin isoforms have distinct roles in assembly. The behavior of the myosins, including nucleation of assembly and determination of filament length, depend upon paramyosin and the core structure as well as their intrinsic molecular properties.