A NATO Advanced study Institute on "Receptors, Membrane Trans­ port and Signal Transduction", was held on the Island of Spet­ sai, Greece, from August 16-27, 1988, in order to consider re­ cent developments in membrane receptor research, membrane trans­ port and signal transduction mechanisms. These topics were put in the larger context of current knowledge on the structure and function of membranes; connections between different fields of research were established by in-depth dis­ cussions of energy transduction and transport mechanisms. The general principles of regulation by signal transduction and protein phosphorylation/dephosphorylation were presented in the context of specific cellular processes. Discussions included al­ so the role of protein tyrosine kinases which are structurally related to oncogene products and, therefore, implicated in va­ rious aspects of cell development and transformation. This book presents the content of the major lectures and a se­ lection of the most relevant posters presented during the course of the Institute. The book is intended to make the proceedings of the Institute accessible to a larger audience and to offer a comprehensive account of those topics on receptors, membrane transport and signal transduction that were discussed extensive­ ly during the course of the Institute. February 1989 The Editors CONTENTS I. G-PROTEINS, ADENYLATE CYCLASE AND PROTEIN PHOSPHORYLATION Selective regulation of G proteins by Cell surface receptors ......... .