E-Book Overview
Small GTPases play a key role in many aspects of contemporary cell biology: control of cell growth and differentiation; regulation of cell adhesion and cell movement; the organization of the actin cytoskeleton; and the regulation of intracellular vesicular transport. This volume plus its companion Volumes 255 and 256 cover all biochemical and biological assays currently in use for analyzing the role of small GTPases in these aspects of cell biology at the molecular level.Volume 257 provides detailed protocols to effectively produce, modify, and assay for the function of small GTPases involved in vesicular traffic through the secretory pathway of eukaryotic cells.
E-Book Content
Preface
As with the Rho and Rab branches of the Ras superfamily of small GTPases, research interest in the Ras branch has continued to expand dramatically into new areas and to embrace new themes since the last Metho&" in Enzymology Volume 255 on Ras GTPases was published in 1995. First, the Ras branch has expanded beyond the original Ras, Rap, and Ral members. New members include M-Ras, Rheb, Rim and Rit. Second, the signaling activities of Ras are much more diverse and complex than appreciated previously. In particular, while the Raf/MEK/ERK kinase cascade remains a key signaling pathway activated by Ras, it is now appreciated that an increasing number of non-Raf effectors also mediate Ras family protein function. Third, it is increasingly clear that the cellular functions regulated by Ras go beyond regulation of cell proliferation, and involve regulation of senescence and cell survival and induction of tumor cell invasion, metastasis, and angiogenesis. Fourth. another theme that has emerged is regulatory cross talk among Ras family proteins, including both GTPase signaling cascades that link signaling from one family member to another, as well as the use of shared regulators and effectors