ACTIN IN DIVIDING CELLS - CONTRACTILE RING FILAMENTS BIND HEAVY MEROMYOSIN
ACTIN IN DIVIDING CELLS - CONTRACTILE RING FILAMENTS BIND HEAVY MEROMYOSIN
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DOI：
10.1073/pnas.70.6.1688
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发表时间：
1973-01-01
影响因子：
11.1
通讯作者：
SCHROEDER, TE
中科院分区：
文献类型：
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作者：
SCHROEDER, TE
HeLa细胞在室温（22°）下用甘油提取后，许多微丝和微管保存良好。在兔骨骼肌的重酶解肌球蛋白中孵育导致收缩环的微丝的明显和特征性的“装饰”。10 mM ATP或2 mM焦磷酸盐完全阻止了装饰，如果重的肌球蛋白被省略或被卵清蛋白（一种非特异性蛋白质）取代，则不会发生装饰。修饰的微丝具有由偏振的重复箭头组成的子结构，所述重复箭头相距27-35 nm。这些结果的特异性强有力地表明，在HeLa细胞的收缩环的微丝是密切相关的肌肉肌动蛋白。在收缩环的微丝之间的非常细的未修饰的股可能代表肌球蛋白组分。这些研究结果进行了讨论方面：肌动球蛋白样的收缩环作为一个机械化学细胞器，导致细胞分裂的性质;可能普遍发生的肌动蛋白样蛋白在所有分裂的动物细胞;和收缩环的细胞松弛素B和重肌球蛋白，组合之间的独特的微丝细胞器的亲和力的组合的敏感性。
Many microfilaments and microtubules are well preserved after glycerol-extraction of HeLa cells at room temperature (22°). Incubation in heavy meromyosin from rabbit skeletal muscle results in conspicuous and characteristic “decoration” of microfilaments of the contractile ring. Decoration is completely prevented by 10 mM ATP or 2 mM pyrophosphate, and fails to occur if heavy meromyosin is either omitted or replaced by egg albumin, a nonspecific protein. Decorated microfilaments have a substructure consisting of polarized, repeating arrowheads 27-35 nm apart. The specificity of these results strongly suggests that microfilaments of the contractile ring in HeLa cells are closely related to muscle actin. Very thin undecorated strands among the microfilaments of the contractile ring possibly represent a myosin component. These findings are discussed in terms of: the actomyosin-like properties of the contractile ring as a mechanochemical organelle that causes cell cleavage; the probable universal occurrence of actin-like protein in all dividing animal cells; and the contractile ring's combined sensitivity to cytochalasin B and its affinity for heavy meromyosin, a combination unique among microfilamentous organelles.