The motility-associated proteins GAP-43, MARCKS, and CAP-23 share unique targeting and surface activity-inducing properties
The motility-associated proteins GAP-43, MARCKS, and CAP-23 share unique targeting and surface activity-inducing properties
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DOI：
10.1006/excr.1997.3709
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发表时间：
1997-10-10
影响因子：
3.7
通讯作者：
Caroni, P
中科院分区：
文献类型：
--
作者：
Wiederkehr, A;Staple, J;Caroni, P
皮质细胞骨架的局部调节控制细胞表面动力学。GAP-43和MARCKS是两种丰富的胞质蛋白激酶C底物，它们通过酰基锚定到细胞膜上并与皮质细胞骨架相互作用。它们中的每一个都涉及到涉及细胞表面的几种运动形式。尽管它们的一级序列没有显示出显著的同源性，GAP-43、MARCKS和皮质细胞凋亡相关蛋白CAP-23（在下文中，这三种蛋白质将缩写为GMC）共享许多特征性的生物化学和生物物理性质以及不寻常的氨基酸组成。在这项研究中，我们确定GMC是否可能在功能上相关。在双标记的免疫细胞化学实验中，GMC积累在独特的表面相关的结构，在那里它们共同分布。在转染的细胞中，GMC诱导细胞形态和细胞表面活性的相同范围的特征性变化，包括突出的水泡和丝状伪足。这些活动与转基因的局部积累相关，并具有局部升高的肌动蛋白动力学的特征，包括应力纤维结构的损失，β-（胞质）肌动蛋白在细胞表面突起处的积累和动态起泡活性。适当的缺失和融合构建体的分析显示，表面积累模式和细胞表面活性相关，最低结构要求包括酰化介导的靶向细胞膜和主要GMC型序列组成的存在。基于这些实验和以前的研究结果GAP-43，MARCKS和CAP-23，我们建议，GMC可能定义一类功能相关的蛋白质，其局部积累促进肌动蛋白动力学和动态结构的形成在细胞周边。叠加在这些一般性质上，膜缔合的调节和效应结构域的结合性质的差异将赋予这些蛋白质中的每一个单独的性质。(C)1997年学术出版社。
Local regulation of the cortical cytoskeleton controls cell surface dynamics. GAP-43 and MARCKS are two abundant cytosolic protein kinase C substrates that are anchored to the cell membrane via acyl groups and interact with the cortical cytoskeleton. Each of them has been implicated in several forms of motility involving the cell surface. Although their primary sequences do not reveal significant homologies, GAP-43, MARCKS, and the cortical cytoskeleton-associated protein CAP-23 (in the following, the three proteins will be abbreviated as GMC) share a number of characteristic biochemical and biophysical properties and an unusual amino acid composition. In this study we determined whether GMC may be related functionally. In double-labeling immunocytochemistry experiments GMC accumulated at unique surface-associated structures, where they codistributed. In transfected cells GMC induced the same range of characteristic changes in cell morphology and cell surface activities, including prominent blebs and filopodia. These activities correlated with local accumulation of transgene and had characteristic features of locally elevated actin dynamics, including loss of stress fiber structures, accumulation of beta-(cytosolic)actin at cell surface protrusions, and dynamic blebbing activity. Analysis of appropriate deletion and fusion constructs revealed that the surface accumulation pattern and cell surface activities were correlated and that minimal structural requirements included acylation-mediated targeting to the cell membrane and the presence of a predominantly GMC-type sequence composition. Based on these experiments and on the results of previous studies on GAP-43, MARCKS, and CAP-23, we propose that GMC may define a class of functionally related proteins whose local accumulation promotes actin dynamics and the formation of dynamic structures at the cell periphery. Superimposed on these general properties, differences in the regulation of membrane association and binding properties of effector domains would confer individual properties to each of these proteins. (C) 1997 Academic Press.