Modification of p115RhoGEF Ser³³⁰ regulates its RhoGEF activity

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• 作者：Christina R. Chow ; Nobuchika Suzuki ; Takeshi Kawamura ; Takao Hamakubo ; Tohru Kozasa
• 关键词：ATRA ; All-trans retinoic acid ; DH ; Dbl homology ; DMEM ; Dulbecco's modified Eagle's medium ; FBS ; Fetal bovine serum ; GAP ; GTPase activating protein ; HPLC&ndash ; MS/MS ; High pressure/tandem mass spectrometry ; LARG ; Leukemia-associated RhoGEF ; LC/MS/MS ; Liqui
• 刊名：Cellular Signalling
• 出版年：2013
• 出版时间：November, 2013
• 年：2013
• 卷：25
• 期：11
• 页码：2085-2092
• 全文大小：793 K

文摘

p115RhoGEF is a member of a family of Rho-specific guanine nucleotide exchange factors that also contains a regulator of G protein signaling homology domain (RH-RhoGEFs) that serves as a link between G¦Á13 signaling and RhoA activation. While the mechanism of regulation of p115RhoGEF by G¦Á13 is becoming well-known, the role of other regulatory mechanisms, such as post-translational modification or autoinhibition, in mediating p115RhoGEF activity is less well-characterized. Here, putative phosphorylation sites on p115RhoGEF are identified and characterized. Mutation of Ser³³⁰ leads to a decrease in serum response element-mediated transcription as well as decreased activation by G¦Á13 in vitro. Additionally, this study provides the first report of the binding kinetics between full-length p115RhoGEF and RhoA in its various nucleotide states and examines the binding kinetics of phospho-mutant p115RhoGEF to RhoA. These data, together with other recent reports on regulatory mechanisms of p115RhoGEF, suggest that this putative phosphorylation site serves as a means for initiation or relief of autoinhibition of p115RhoGEF, providing further insight into the regulation of its activity.