In the last few years, the functional divergence of GTPases has attracted the attention of many researchers in structural biology, cell biology, cell growth and differentiation and developmental biology. Numerous studies have contributed important data on the biochemical features, intracellular localization, and functions of these proteins. This book is a summation of the information compiled so far on this family of proteins. An opening section introduces the different subfamilies and the structural features of their various members. The following chapters focus on the individual GTPases, their regulatory components and effector proteins. Intended to serve as an easy-to-use reference, this guidebook will be valued equally by experienced researchers and investigators beginning work in this expanding field.