DOCK2 associates with CrkL and regulates Rac1 in human leukemia cell lines
DOCK2 associates with CrkL and regulates Rac1 in human leukemia cell lines
复制标题
DOI：
10.1182/blood-2001-11-0032
复制
发表时间：
2002-12-01
期刊：
影响因子：
20.3
通讯作者：
Tanaka, S
中科院分区：
文献类型：
--
作者：
Nishihara, H;Maeda, M;Tanaka, S
CDM（秀丽隐杆线虫的ced-5、人的DOCK 180 [分子量为180 kDa的Crk下游]和黑腹果蝇的成肌细胞city）蛋白家族已被证明在贴壁细胞中的衔接分子c-CT 10相关激酶II（c-Crk-II）的调节下在整合素介导的信号通路中起关键作用。最近，造血细胞特异性CDM蛋白DOCK 2已被证明是淋巴细胞迁移所不可或缺的。然而，DOCK 2的调节机制仍然是未知的，因为DOCK 2缺乏c-Crk-II结合共有基序。在本研究中，我们证明了DOCK 2结合CrkL，这是专门存在于造血细胞在体内和体外，我们还发现，两个独立的区域的DOCK 2有助于其结合CrkL的Src同源3（SH 3）域。使用Jurkat细胞通过免疫细胞化学分析显示DOCK 2与Crk样（CrkL）和F-肌动蛋白的共定位。我们还发现，在293 T细胞中，CrkL诱导的小鸟嘌呤三磷酸酶（GTdR）Rac 1的激活被DOCK 2-dCS突变体显著抑制。此外，在Jurkat细胞中证明了DOCK 2与Rac 1的鸟嘌呤核苷酸交换因子（GEF）Vav的关联。最后，DOCK 2-dCS突变体在Jurkat细胞中的稳定表达显示减少细胞附着。这些数据表明，存在一种新的蛋白质复合物的CrkL，DOCK 2，和Vav调节Rac 1在白血病细胞系。(C)2002年，美国血液学会。
The CDM (ced-5 of Caenorhabditis elegans, DOCK180 [downstream of Crk with molecular weight of 180 kDa] of humans, and myoblast city of Drosophila melanogaster) family of proteins has been shown to play a pivotal role in the integrin-mediated signaling pathway under the regulation of an adaptor molecule c-CT10- related kinase II (c-Crk-II) in adherent cells. Recently, hematopoietic cell-specific CDM protein DOCK2 has been shown to be indispensable for lymphocyte migration. However, the regulatory mechanism for DOCK2 is still unknown because DOCK2 lacks a c-Crk-II binding consensus motif. In this study, we demonstrated that DOCK2 bound to CrkL, which is present exclusively in hematopoietic cells both in vivo and in vitro, and we also found that 2 separate regions of DOCK2 contributed to its binding to Src homology 3 (SH3) domain of CrkL. Colocalization of DOCK2 with Crk-like (CrkL) and F-actin was shown by immunocytochemical analysis with the use of Jurkat cells. We also found that CrkL-induced activation of small guanine triphosphatase (GTPase) Rac1 was significantly inhibited by the DOCK2-dCS mutant in 293T cells. Furthermore, the association of DOCK2 and Vav, the guanine-nucleotide exchanging factor (GEF) for Rac1, was demonstrated in Jurkat cells. Finally, the stable expression of DOCK2-dCS mutant in Jurkat cells was shown to reduce cell attachment. These data suggest the presence of a novel protein complex of CrkL, DOCK2, and Vav to regulate Rac1 in leukemia cell lines. (C) 2002 by The American Society of Hematology.