A novel Dictyostelium RasGEF is required for normal endocytosis, cell motility and multicellular development
A novel Dictyostelium RasGEF is required for normal endocytosis, cell motility and multicellular development
复制标题
正常的内吞作用、细胞运动和多细胞发育需要一种新型盘基网柄菌 RasGEF
DOI：
10.1016/s0960-9822(00)00797-1
复制
发表时间：
2000
期刊：
影响因子：
9.2
通讯作者：
R. Insall
中科院分区：
文献类型：
--
作者：
A. Wilkins;Jonathan R. Chubb;R. Insall
背景：网柄藻具有大量Ras蛋白，但其激活因子鸟嘌呤核苷酸交换因子（GEFs）的研究却很少。目前还不清楚，在Dictyostelium或在高等真核生物中，Ras途径是否是线性的，每个Ras由自己的GEF控制，或网络化，多个GEF作用于多个Ras蛋白质。结果：我们已经确定了theDictyostelium基因编码的RasGEFB，一种蛋白质与已知的RasGEF，如儿子的七（Sos）蛋白质的同源性。Dictyostelium细胞中，RasGEFB基因被破坏移动异常迅速，但失去了执行巨胞饮的能力，因此在液体培养基中生长。冠，大胞饮的网站，被极化板状伪足取代。突变细胞在早期发育中也有严重缺陷，尽管它们最终形成了微小但比例正常的子实体。这种缺陷与盘状蛋白Iγ mRNA的缺失有关，这是一种饥饿诱导的基因，尽管发育所需的其他基因表达正常甚至早熟。结论：RasGEFB可能是RasS蛋白的主要激活因子，RasS蛋白调节巨胞饮和细胞速度，但RasGEFB似乎也调节一个或多个其它Ras蛋白。
Background:Dictyosteliumpossesses a surprisingly large number of Ras proteins and little is known about their activators, the guanine nucleotide exchange factors (GEFs). It is also unclear, inDictyosteliumor in higher eukaryotes, whether Ras pathways are linear, with each Ras controlled by its own GEF, or networked, with multiple GEFs acting on multiple Ras proteins.Results:We have identified theDictyosteliumgene that encodes RasGEFB, a protein with homology to known RasGEFs such as the Son-of-sevenless (Sos) protein.Dictyosteliumcells in which the gene for RasGEFB was disrupted moved unusually rapidly, but lost the ability to perform macropinocytosis and therefore to grow in liquid medium. Crowns, the sites of macropinocytosis, were replaced by polarised lamellipodia. Mutant cells were also profoundly defective in early development, although they eventually formed tiny but normally proportioned fruiting bodies. This defect correlated with loss of discoidin Iγ mRNA, a starvation-induced gene, although other genes required for development were expressed normally or even precociously. RasGEFB was able to rescue aSaccharomyces CDC25mutant, indicating that it is a genuine GEF for Ras proteins.Conclusions:RasGEFB appears to be the principal activator of the RasS protein, which regulates macropinocytosis and cell speed, but it also appears to regulate one or more other Ras proteins.
登录
查看更多内容
darlin 的鉴定，一种具有犰狳样重复序列的盘基网柄菌蛋白，可与小 GTP 酶结合，对于发育中细胞的正确聚集非常重要。
影响因子：
3.3
作者：
Vithalani,KK;Parent,CA;Thorn,EM;Penn,M;Larochelle,DA;Devreotes,PN;DeLozanne,A
通讯作者：
DeLozanne,A
影响因子：
56.9
作者：
CHARDIN, P;CAMONIS, JH;BARSAGI, D
通讯作者：
BARSAGI, D
盘基网柄菌 PI3K 基因的破坏会降低 [32P] 磷脂酰肌醇 3,4 二磷酸和 [32P] 磷脂酰肌醇三磷酸水平，改变 F-肌动蛋白分布并损害胞饮作用。
影响因子：
4
作者：
Zhou,K;Pandol,S;Bokoch,G;Traynor-Kaplan,AE
通讯作者：
Traynor-Kaplan,AE
小鼠 sos1 基因产物的催化结构域在体内和体外激活 Ras 蛋白。
影响因子：
8
作者：
Liu,BX;Wei,W;Broek,D
通讯作者：
Broek,D
影响因子：
56.9
作者：
BARSAGI, D;FERAMISCO, JR
通讯作者：
FERAMISCO, JR