The IQGAP-related protein DGAP1 interacts with Rac and is involved in the modulation of the F-actin cytoskeleton and control of cell motility.
The IQGAP-related protein DGAP1 interacts with Rac and is involved in the modulation of the F-actin cytoskeleton and control of cell motility.
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IQGAP 相关蛋白 DGAP1 与 Rac 相互作用，参与 F-肌动蛋白细胞骨架的调节和细胞运动的控制。
作者：
J. Faix;C. Clougherty;A. Konzok;Ursula Mintert;J. Murphy;R. Albrecht;B. Mühlbauer;J. Kuhlmann
DGAP 1是盘基网柄藻细胞皮层相关的95 kDa蛋白，与RasGTP酶激活蛋白（RasGAP）和RasGAP相关蛋白具有同源性。当检测RasGAP活性时，重组DGAP 1蛋白在体外不促进人H-Ras或网骨藻RasG的GT3活性。相反，DGAP 1结合到网骨藻Rac 1A和人Rac 1，但不结合到人Cdc 42。DGAP 1优先与Rac 1和Rac 1A的活化GTP结合形式相互作用，但不影响GTP酶活性。由于Rho型GTP酶与特定F-肌动蛋白结构的形成和细胞形态的控制有关，因此对缺乏或过表达DGAP 1的突变体的微丝系统进行了分析。DGAP 1无效突变体显示F-肌动蛋白水平升高，这是在大的前缘，膜皱褶或许多大的丝状体组织。肌动蛋白融合绿色荧光蛋白（GFP）的表达被用来监测这些细胞中的肌动蛋白动力学，并且揭示了DGAP 1缺失细胞的F-肌动蛋白细胞骨架被迅速重新排列以形成皱褶和丝状足。相反，在DGAP 1过表达细胞中，含有F-肌动蛋白的细胞突起的形成在很大程度上受到抑制。细胞迁移的测量表明，DGAP 1的表达与细胞运动的速度呈负相关。
DGAP1 of Dictyostelium discoideum is a cell cortex associated 95 kDa protein that shows homology to both RasGTPase-activating proteins (RasGAPs) and RasGAP-related proteins. When tested for RasGAP activity, recombinant DGAP1 protein did not promote the GTPase activity of human H-Ras or of Dictyostelium RasG in vitro. Instead, DGAP1 bound to Dictyostelium Rac1A and human Rac1, but not to human Cdc42. DGAP1 preferentially interacted with the activated GTP-bound forms of Rac1 and Rac1A, but did not affect the GTPase activities. Since Rho-type GTPases are implicated in the formation of specific F-actin structures and in the control of cell morphology, the microfilament system of mutants that either lack or overexpress DGAP1 has been analysed. DGAP1-null mutants showed elevated levels of F-actin that was organised in large leading edges, membrane ruffles or numerous large filopods. Expression of actin fused to green fluorescent protein (GFP) was used to monitor the actin dynamics in these cells, and revealed that the F-actin cytoskeleton of DGAP1-null cells was rapidly re-arranged to form ruffles and filopods. Conversely, in DGAP1-overexpressing cells, the formation of cellular projections containing F-actin was largely suppressed. Measurement of cell migration demonstrated that DGAP1 expression is inversely correlated with the speed of cell motility.
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Ras GAP 对于盘基网柄菌的胞质分裂和空间模式至关重要。
DOI：
10.1242/dev.124.5.983
发表时间：
1997
期刊：
Development (Cambridge, England)
影响因子：
--
作者：
Lee,S;Escalante,R;Firtel,RA
通讯作者：
Firtel,RA
DOI：
--
发表时间：
1994-08
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
L. Weissbach;J. Settleman;M. Kalady;A. Snijders;A. Murthy;Yu-xin Yan;A. Bernards
通讯作者：
L. Weissbach;J. Settleman;M. Kalady;A. Snijders;A. Murthy;Yu-xin Yan;A. Bernards
影响因子：
3.5
作者：
BUSH, J;FRANEK, K;CARDELLI, J
通讯作者：
CARDELLI, J
盘基网柄菌中的肌动蛋白相关蛋白。
DOI：
10.1002/dvg.1020110503
发表时间：
1990
期刊：
Developmental genetics
影响因子：
--
作者：
Luna,EJ;Condeelis,JS
通讯作者：
Condeelis,JS
影响因子：
56.9
作者：
CUNNINGHAM, CC;STOSSEL, TP;KWIATKOWSKI, DJ
通讯作者：
KWIATKOWSKI, DJ