Microtubule-associated protein 2c reorganizes both microtubules and microfilaments into distinct cytological structures in an actin-binding protein-280-deficient melanoma cell line.
Microtubule-associated protein 2c reorganizes both microtubules and microfilaments into distinct cytological structures in an actin-binding protein-280-deficient melanoma cell line.
复制标题
微管相关的蛋白2C在肌动蛋白结合蛋白280缺陷型黑色素瘤细胞系中重新组织微管和微丝中的微丝。
DOI：
10.1083/jcb.136.4.845
复制
发表时间：
1997-02-24
影响因子：
7.8
通讯作者：
Kosik, K S
中科院分区：
文献类型：
--
作者：
Cunningham, C C;Leclerc, N;Flanagan, L A;Lu, M;Janmey, P A;Kosik, K S
细胞突起的出现往往涉及到微管和微丝之间的相互作用。这两个细胞骨架系统之间的相互作用在神经元生长锥体中尤为明显。神经元微管相关蛋白2(MAP2c)的幼年亚型存在于生长锥体中，我们推测它介导了微丝和微管之间的相互作用。为了在体内解决这个问题，我们使用了人类黑色素瘤细胞M2，它缺乏肌动蛋白结合蛋白-280(ABP-280)并形成膜泡，这在野生型或ABP转基因细胞中是看不到的。微量注射tau或成熟的MAP2可挽救起泡表型；MAP2c不仅使起泡停止，而且诱导形成两种不同的细胞结构。这些是富含肌动蛋白的板层，通常包括膜褶皱和微管承载突起。细胞松弛素D处理后板层塌陷，秋水仙素处理后突起回缩。MAP2c免疫细胞化学染色显示在细胞中缺乏微管蛋白的区域，如板层内和与膜褶皱相关的区域。体外流变学证实，MAP2c是一种高效的肌动蛋白凝胶蛋白，能够在非常低的浓度下将肌动蛋白细丝组织成各向同性的阵列；tau和成熟的MAP2不具有这种流变性。这些结果表明，MAP2c不仅参与了与微管的功能特异性相互作用，也参与了与微丝的功能特异性相互作用。
The emergence of processes from cells often involves interactions between microtubules and microfilaments. Interactions between these two cytoskeletal systems are particularly apparent in neuronal growth cones. The juvenile isoform of the neuronal microtubule-associated protein 2 (MAP2c) is present in growth cones, where we hypothesize it mediates interactions between microfilaments and microtubules. To approach this problem in vivo, we used the human melanoma cell, M2, which lacks actin-binding protein-280 (ABP-280) and forms membrane blebs, which are not seen in wild-type or ABP-transfected cells. The microinjection of tau or mature MAP2 rescued the blebbing phenotype; MAP2c not only caused cessation of blebbing but also induced the formation of two distinct cellular structures. These were actin-rich lamellae, which often included membrane ruffles, and microtubule-bearing processes. The lamellae collapsed after treatment with cytochalasin D, and the processes retracted after treatment with colchicine. MAP2c was immunocytochemically visualized in zones of the cell that were devoid of tubulin, such as regions within the lamellae and in association with membrane ruffles. In vitro rheometry confirmed that MAP2c is an efficient actin gelation protein capable of organizing actin filaments into an isotropic array at very low concentrations; tau and mature MAP2 do not share this rheologic property. These results suggest that MAP2c engages in functionally specific interactions not only with microtubules but also with microfilaments.