Integrin-dependent translocation of phosphoinositide 3-kinase to the cytoskeleton of thrombin-activated platelets involves specific interactions of p85 alpha with actin filaments and focal adhesion kinase.
Integrin-dependent translocation of phosphoinositide 3-kinase to the cytoskeleton of thrombin-activated platelets involves specific interactions of p85 alpha with actin filaments and focal adhesion kinase.
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整联蛋白依赖性的磷酸肌醇3-激酶与凝血酶激活血小板的细胞骨架的转运涉及p85α与肌动蛋白丝和粘着斑激酶的特定相互作用。
DOI：
10.1083/jcb.129.3.831
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发表时间：
1995-05
影响因子：
7.8
通讯作者：
CHAP, H
中科院分区：
文献类型：
--
作者：
GUINEBAULT, C;PAYRASTRE, B;RACAUDSULTAN, C;MAZARGUIL, H;BRETON, M;MAUCO, G;PLANTAVID, M;CHAP, H
凝血酶诱导的磷脂酰肌醇3,4-二磷酸（PtdIns(3,4)P2）而非PtdIns(3,4,5,)P3的积累与29%的磷酸肌醇激酶（PtdIns 3-激酶）的p85 α调控亚基向细胞骨架的迁移密切相关，并伴随着PtdIns 3-激酶活性在该亚细胞部分的显著增加。实际上，PtdIns(3,4)P2积累和PtdIns 3-激酶、pp60c-src和p125FAK易位以及聚集是肌动蛋白聚合后发生的伴随事件，具有明显的滞后性。PtdIns(3,4)P2的积累和PtdIns 3-激酶在细胞骨架上的重新定位都依赖于酪氨酸磷酸化、整合素信号传导和聚集。此外，尽管在从凝血酶活化的血小板细胞骨架中获得的抗磷酸酪氨酸免疫沉淀物中检测到p85 α，但我们未能证明细胞骨架p85 α的酪氨酸磷酸化。Tyrphostin处理明显减少了p85 α在亚细胞部分的存在，表明p85 α与磷酸化酪氨酸蛋白存在物理相互作用。这些数据使我们研究能够在细胞骨架中与PtdIns 3-激酶相互作用的蛋白质。我们发现这种酶与肌动蛋白丝的关联：这种相互作用在体外肌动蛋白解聚-再聚合一个周期后自发恢复。这种与f -肌动蛋白的关联似乎至少部分是间接的，因为我们证明了p85 α与酪氨酸磷酸化的细胞骨架局灶粘附激酶p125FAK的富含脯氨酸的序列存在凝血酶依赖性相互作用。此外，我们发现p125FAK富含脯氨酸的序列结合p85 α亚基的src同源3结构域显著激活PtdIns 3-激酶。这种相互作用可能代表了PtdIns 3-激酶在细胞特定区域激活的新机制，并表明与肌动蛋白丝相连的局灶接触样区域在α IIb/ β 3整合素配体结合和凝血酶引起的血小板聚集时发生的信号事件中起关键作用。
Thrombin-induced accumulation of phosphatidylinositol 3,4-bisphosphate (PtdIns(3,4)P2) but not of PtdIns(3,4,5,)P3 is strongly correlated with the relocation to the cytoskeleton of 29% of the p85 alpha regulatory subunit of phosphoinositide 3-kinase (PtdIns 3-kinase) and is accompanied by a significant increase in PtdIns 3-kinase activity in this subcellular fraction. Actually, PtdIns(3,4)P2 accumulation and PtdIns 3-kinase, pp60c-src, and p125FAK translocations as well as aggregation were concomitant events occurring with a distinct lag after actin polymerization. The accumulation of PtdIns(3,4)P2 and the relocalization of PtdIns 3-kinase to the cytoskeleton were both dependent on tyrosine phosphorylation, integrin signaling, and aggregation. Furthermore, although p85 alpha was detected in anti- phosphotyrosine immunoprecipitates obtained from the cytoskeleton of thrombin-activated platelets, we failed to demonstrate tyrosine phosphorylation of cytoskeletal p85 alpha. Tyrphostin treatment clearly reduced its presence in this subcellular fraction, suggesting a physical interaction of p85 alpha with a phosphotyrosyl protein. These data led us to investigate the proteins that are able to interact with PtdIns 3-kinase in the cytoskeleton. We found an association of this enzyme with actin filaments: this interaction was spontaneously restored after one cycle of actin depolymerization-repolymerization in vitro. This association with F-actin appeared to be at least partly indirect, since we demonstrated a thrombin-dependent interaction of p85 alpha with a proline-rich sequence of the tyrosine-phosphorylated cytoskeletal focal adhesion kinase, p125FAK. In addition, we show that PtdIns 3-kinase is significantly activated by the p125FAK proline-rich sequence binding to the src homology 3 domain of p85 alpha subunit. This interaction may represent a new mechanism for PtdIns 3-kinase activation at very specific areas of the cell and indicates that the focal contact-like areas linked to the actin filaments play a critical role in signaling events that occur upon ligand engagement of alpha IIb/beta 3 integrin and platelet aggregation evoked by thrombin.
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影响因子：
4.1
作者：
KING, WG;KUCERA, GL;RITTENHOUSE, SE
通讯作者：
RITTENHOUSE, SE
影响因子：
5.3
作者：
ESCOBEDO, JA;KAPLAN, DR;WILLIAMS, LT
通讯作者：
WILLIAMS, LT
影响因子：
5.3
作者：
FUKUI, Y;HANAFUSA, H
通讯作者：
HANAFUSA, H
影响因子：
7.8
作者：
Huang, M M;Lipfert, L;Cunningham, M;Brugge, J S;Ginsberg, M H;Shattil, S J
通讯作者：
Shattil, S J
DOI：
10.1073/pnas.91.21.10148
发表时间：
1994-10-11
影响因子：
11.1
作者：
CHEN, HC;GUAN, JL
通讯作者：
GUAN, JL