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 ......... .