Raichu-RalA

A. Takaya, Y. Ohba, K. Kurokawa, and M. Matsuda. RalA activation at nascent lamellipodia of EGF-stimulated Cos7 cells and migrating MDCK cells. Mol.Biol.Cell 15:2549-2557, 2004.

RalA, a member of the Ras-family GTPases, regulates various cellular functions such as filopodia formation, endocytosis, and exocytosis. Upon epidermal growth factor (EGF) stimulation, activated Ras recruits guanine nucleotide exchange factors (GEFs) for RalA, followed by RalA activation. By using FRET-based probes for RalA activity (see below), we found that the EGF-induced RalA activation in Cos7 cells was restricted at the EGF-induced nascent lamellipodia, whereas under a similar condition both Ras activation and Ras-dependent translocation of Ral GEFs occurred more diffusely at the plasma membrane.

Video images of RalA activation upon EGF stimulation.

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