Stimulus-dependent disorganization of actin filaments induced by overexpression of cofilin in C2 myoblasts
Stimulus-dependent disorganization of actin filaments induced by overexpression of cofilin in C2 myoblasts
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DOI：
10.1247/csf.21.491
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发表时间：
1996-12-01
影响因子：
1.5
通讯作者：
Obinata, T
中科院分区：
文献类型：
--
作者：
Ono, S;Abe, H;Obinata, T
肌动蛋白解聚因子（ADF）/cofilin是一个广泛分布的肌动蛋白结合蛋白家族，以pH依赖的方式调节肌动蛋白的聚合。在培养的细胞中，cofilin以及ADF与肌动蛋白一起从细胞质易位到细胞核中，并响应于热休克或二甲基亚砜（DMSO）处理而形成棒状结构。为了研究cofilin与肌动蛋白的体内相互作用，我们研究了cofilin过表达对C2成肌细胞中肌动蛋白细胞骨架的影响。有趣的是，与正常细胞相比，在过表达cofilin的细胞中没有观察到对鬼笔环肽染色模式的显著影响。然而，在用DMSO处理后，细胞质肌动蛋白丝被破坏，并且含有cofilin和肌动蛋白的核内杆结构在过表达cofilin的细胞中比在正常细胞中明显更大和更厚。热休克也刺激破坏的微丝和形成的核内和突出的细胞质cofilin-actin杆cofilin转染细胞，表明DMSO处理或热休克触发cofilin-actin相互作用。我们进一步发现，肌球蛋白ATP酶抑制剂（BDM）诱导减少细胞质染色与鬼笔环肽在cofilin转染的细胞。结果提示，肌球蛋白活性可能参与了体内cofilin-actin相互作用的调节。
Actin depolymerizing factor (ADF)/cofilin is a widely distributed family of actin-binding proteins which regulate actin polymerization in a pH-dependent manner. In cultured cells, cofilin, as well as ADF, translocates from the cytoplasm into the nucleus together with actin and forms rod-like structures in response to heat shock or dimethylsulfoxide (DMSO) treatment. In order to study in vivo interaction of cofilin with actin, we examined the effects of cofilin overexpression on actin cytoskeleton in C2 myoblasts. Interestingly, no remarkable effect was observed on phalloidin-stained patterns in cells overexpressing cofilin as compared with normal cells. However, upon treatment with DMSO, cytoplasmic actin filaments were disrupted and intranuclear rod structures containing cofilin and actin were apparently larger and thicker in cells overexpressing cofilin than in normal cells. Heat shock also stimulated disruption of microfilaments and formation of both intranuclear and prominent cytoplasmic cofilin-actin rods in cofilin-transfected cells, suggesting that DMSO-treatment or heat shock triggers cofilin-actin interaction. We further found that a myosin ATPase inhibitor (BDM) induced a reduction in cytoplasmic staining with phalloidin in cofilin-transfected cells. The results suggest that myosin activity might be involved in the regulation of cofilin-actin interaction in vivo.