GAP43, MARCKS, and CAP23 modulate PI(4,5)P(2) at plasmalemmal rafts, and regulate cell cortex actin dynamics through a common mechanism.
GAP43, MARCKS, and CAP23 modulate PI(4,5)P(2) at plasmalemmal rafts, and regulate cell cortex actin dynamics through a common mechanism.
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DOI：
10.1083/jcb.149.7.1455
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发表时间：
2000-06-26
期刊：
影响因子：
--
通讯作者：
Caroni P
中科院分区：
文献类型：
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作者：
Laux T;Fukami K;Thelen M;Golub T;Frey D;Caroni P
细胞皮层及其肌动蛋白细胞骨架的动态特性决定了细胞行为的重要方面，并且是细胞调节的主要目标。GAP 43、豆蔻酰化富含丙氨酸的C激酶底物（MARCKS）和CAP 23（GMC）是局部丰富的质膜相关PKC底物，其影响肌动蛋白细胞骨架。它们的表达与形态发生过程和细胞运动相关，但它们在皮层调节中的作用一直难以从机制上定义。我们现在表明，这三种蛋白质积累在筏，在那里它们与PI（4，5）P2共分布，并促进其保留和聚类。PI（4，5）P2的结合和调节依赖于这些蛋白的基本效应结构域（艾德），并且缺乏艾德的构建体作为质膜PI（4，5）P2调节的显性抑制剂起作用。在神经元样细胞系中，PC12、NGF和底物诱导的外周肌动蛋白结构和神经突生长被这三种蛋白中的任何一种大大增强，并被Δ艾德突变体抑制。全局掩蔽PI（4，5）P2的试剂模拟GMC对外周肌动蛋白募集和细胞铺展的作用，但干扰极化和过程形成。显性负性GAP 43（Δ艾德）也干扰转基因小鼠的周围神经再生、刺激诱导的神经发芽和神经肌肉接头处解剖可塑性的控制。这些结果表明，GMC是功能和机制相关的PI（4，5）P2调节蛋白，上游的肌动蛋白和细胞皮质动力学调节。
The dynamic properties of the cell cortex and its actin cytoskeleton determine important aspects of cell behavior and are a major target of cell regulation. GAP43, myristoylated alanine-rich C kinase substrate (MARCKS), and CAP23 (GMC) are locally abundant, plasmalemma-associated PKC substrates that affect actin cytoskeleton. Their expression correlates with morphogenic processes and cell motility, but their role in cortex regulation has been difficult to define mechanistically. We now show that the three proteins accumulate at rafts, where they codistribute with PI(4,5)P2, and promote its retention and clustering. Binding and modulation of PI(4,5)P2 depended on the basic effector domain (ED) of these proteins, and constructs lacking the ED functioned as dominant inhibitors of plasmalemmal PI(4,5)P2 modulation. In the neuronlike cell line, PC12, NGF- and substrate-induced peripheral actin structures, and neurite outgrowth were greatly augmented by any of the three proteins, and suppressed by ΔED mutants. Agents that globally mask PI(4,5)P2 mimicked the effects of GMC on peripheral actin recruitment and cell spreading, but interfered with polarization and process formation. Dominant negative GAP43(ΔED) also interfered with peripheral nerve regeneration, stimulus-induced nerve sprouting and control of anatomical plasticity at the neuromuscular junction of transgenic mice. These results suggest that GMC are functionally and mechanistically related PI(4,5)P2 modulating proteins, upstream of actin and cell cortex dynamics regulation.