286 Current Topics in Microbiology and Immunology Editors R.W. Compans, Atlanta/Georgia M.D. Cooper, Birmingham/Alabama T. Honjo, Kyoto· H. Koprowski, Philadelphia/Pennsylvania F. Melchers, Basel· M.B.A. Oldstone, La Jolla/California S. Olsnes, Oslo· M. Potter, Bethesda/Maryland P.K. Vogt, La Jolla/California· H. Wagner, Munich Springer-Verlag Berlin Heidelberg GmbH I.H. Madshus (Ed.) Signalling from Internalized Growth Factor Receptors With 19 Figures Springer Professor Inger Helene Madshus, M.D., Ph.D. Institute of Pathology Rikshospitalet University Hospital 0027 Oslo Norway e-mail: [email protected] Cover illustration by LH. Madshus The receptor tyrosine kinase ErbB2 (green) is over-expressed in the breast carcinoma cell line SKBr3. ErbB2 is endocytosis deficient and excluded from early endosome antigen positive endosomes (blue). ISSN 0070-217X ISBN 978-3-642-05912-4 ISBN 978-3-540-69494-6 (eBook) DOI 10.1007/978-3-540-69494-6 Library of Congress Catalog Card Number 72-152360 This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically the rights of translation, reprinting, reuse of illustrations, recitation, broadcasting, reproduction on microfilms or in any other way, and storage in data banks. Duplication of this publication or parts thereof is permitted only under the provisions of the German Copyright Law of September 9, 1965, in its current version, and permission for use must always be obtained from Springer· Verlag. Violations are liable for prosecution under the German Copyright Law. © Springer-Verlag Berlin Heidelberg 2004 Originally published by Springer-Verlag Berlin Heidelberg New York in 2004 Softcover reprint of the hardcover I st edition 2004 The use of general descriptive names, registered names, trademarks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. Product liability: The publishers cannot quarantee that accuracy of any information about dosage and application contained in this book. In every individual case the user must check such information by consulting the relevant literature. Editor: Dr. Rolf Lange, Heidelberg Desk editor: Anne Clauss, Heidelberg Production editor: Andreas Gosling, Heidelberg Cover design: design & production GmbH, Heidelberg Typesetting: StUrtz AG, WUrzburg Printed on acid-free paper - 27/3150 ag 5432 1 0 Preface Mammalian cells are to a large extent controlled by the environment. Dif fusible factors (growth factors, cytokines, and hormones) released by oth er cells in the body bind to and activate receptors localized at the cell sur face. In the case of the fibroblast growth factor receptor, there seems to be receptors both at the plasma membrane and in the nucleus. Cellular recep tors control growth, apoptosis, immune function, differentiation, develop ment, and upon dysregulation, cancer progression and metastasis. Upon li gand binding, most receptors are internalized. However, the mechanisms of endocytosis are diverse, and receptors are taken into cells from different membrane microdomains. Activation of receptors results in two important interconnected processes, namely, signal transduction and endocytosis. In terestingly, signal transduction controls endocytosis and endocytosis con trols signalling. In both processes sequential formation of transient protein machineries is crucial. Currently, characterization of such complex ma chineries is advancing rapidly. It has recently become appreciated that sev eral post-translational modifications directly control the affinity of pro tein-protein interactions. This volume of Current Topics in Microbiology and Immunology focuses on the recent understanding of signalling from in ternalized activated growth factor receptors. This includes information on pathways by which the rate and specificity of endocytosis and intracellular sorting are controlled. It further includes information on how specialized signalling and trafficking platforms are formed at the plasma membrane and on intracellular vesicles. Recent advances in cell biology and bioinfor matics have revealed the existence of several conserved protein modules, such as UIM, UEV, UBA, and CUE domains, that endow proteins with the ability to bind the small, conserved peptide ubiquitin. Ubiquitination thereby turns out to be a key process in controlling affinity and specificity of protein interactions and therefore in controlling both signal transduc tion and intracellular transport. As discussed in the chapter by Sigismund et aI., evidence is accumulating that monoubiquitination, in addition to controlling membrane trafficking of receptors, controls histone function, transcription regulation, DNA repair, and DNA replication. This opens up a new and exciting avenue in science that will eventually shed light on some of the fundamental and complex processes of cell biology. Inger Helene Madshus List of Contents Receptor Tyrosine Kinase Signaling and Trafficking Paradigms Revisited M.A. Barbieri, T.P. Ramkumar, S. Fernadez-Pol, P.I. Chen, and. P.D. Stahl. ............................................ . Met Receptor Dynamics and Signalling D.E. Hammond, S. Carter, and M.J. Clague 21 Signaling, Internalization, and Intracellular Activity of Fibroblast Growth Factor A. Wifdlocha and V. S0rensen. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 Ubiquitin System-Dependent Regulation of Growth Hormone Receptor Signal Transduction G.J. Strous, C. Alves dos Santos, J. Gent, R. Govers, M. Sachse, J. Schant!, and P. van Kerkhof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81 Clathrin-Independent Endocytosis and Signalling of Interleukin 2 Receptors IL-2R Endocytosis and Signalling F. Gesbert, N. Sauvonnet, and A. Dautry-Varsat. . . . . . . . . . . . . . . . . .. 119 Signaling Through Monoubiquitination S. Sigismund, S. Polo, and P.P. Di Fiore ......................... 149 Subject Index ............................................. 187 List of Contributors (Their addresses can be found at the beginning of their respective chapters.) Alves dos Santos, C. 81 Kerkhof, P. van 81 Barbieri, M.A. Polo, S. 149 Carter, S. 21 Ramkumar, T.P. 1 Chen, P.I. 1 Sachse, M. 81 Clague, M.J. 21 Sauvonnet, N. 119 Dautry-Varsat, A. 119 Schantl, J. 81 Di Fiore, P.P. 149 Sigismund, S. 149 Fernadez-Pol, S. S0rensen, V. 45 Gent, J. 81 Stahl, P.D. Gesbert, F. 119 Strous, G.J. 81 Govers, R. 81 Wicrdlocha, A. 45 Hammond, D.E. 21 CTMI (2004) 286:1-19 © Springer-Verlag 2004 Receptor Tyrosine Kinase Signaling and Trafficking-Paradigms Revisited M. A. Barbieri· T. P. Ramkumar· S. Fernadez-Pol· P. 1. Chen· P. D. Stahl (~) Department of Cell Biology and Physiology, School of Medicine, Washington University, 660 S. Euclid Avenue, Campus Box 8228, St. Louis, MO 63110, USA pstahl@cellbiology. wustl.edu Introduction . . . . . . . . . . . . . 2 Endocytosis of Signaling Receptor . 2 3 Receptor Trafficking: Endocytic Regulation of Signaling Pathways . 4 4 Signaling in Endosomes . 7 5 Sorting in Endosomes . . 11 6 A Perspective on Signaling Endosomes 13 References. . . . . . . . . . . . . . . . . . . . . 14 Abstract The recognition of growth factors and other cell signaling agents by their cognate cell surface receptors triggers a cascade of signal transducing events. Ligand binding and subsequent activation of many signal transducing receptors increases their rate of internalization. Endocytosis of the receptor has always been viewed as primarily a mechanism for signal attenuation and receptor degradation, but recent evidence suggests that internalization may result in the formation of specialized sig naling platforms on intracellular vesicles. Thus, understanding how interactions be tween receptors and intracellular signaling molecules, such as adaptors, GTPases, and kinases, are regulated will undoubtedly provide insight into the ways that cells sense and adapt to the extracellular milieu. 1 Introduction Signaling from the extracellular environment is achieved through un ique, dynamic, and efficient signal transduction systems. The first cellu lar components that come in contact with external signals are cell sur face receptors. Receptor tyrosine kinases (RTKs) constitute a large 2 M.A. Barbieri et al. group of receptors that respond to growth factors and have intrin sic tyrosine kinase activity. On ligand binding, RTKs dimerize and, through a conformation change, intrinsic cytoplasmic kinase activity is switched on, which in turn results in autophosphorylation of the RTK (Schlessinger 2000; Neer 1995). Autophosphorylation of tyrosine resi dues in receptors creates binding sites for proteins containing Src-ho mology-2 (SH2) and phosphotyrosine-binding (PTB) domains. These interacting proteins may serve as adaptors and/or show enzymatic activ ities [e.g., ligand-regulated guanine nucleotide exchange factors (GEFs) that regulate the function of the particular RTKJ. Alteration of either the adaptor function or the enzymatic activity may affect the cascade of protein-protein and protein-lipid interactions, phosphorylations, and dephosphorylations, and the production of secondary messengers, that lead ultimately to altered gene transcription and cellular function. It has been observed that many RTKs are rapidly endocytosed on li gand activation, after which they traffic through the endomembrane net work, an elaborate system of interconnecting tubules and vesicles that mediate the transport of fluid and selected membrane proteins. The sug gestion that these endocytic membranes have a role in cell signaling has been an open question. Cell surface receptors have also served as model systems for the study of general mechanisms and pathways of endocytic transport. Early stud ies of the relationship between signaling and endocytosis relied mostly on the use of subcellular fractionation of membrane compartments and on the analysis of receptors harboring mutations. More recently, experi mental approaches to interfere with specific mechanisms of membrane transport have been developed, allowing a detailed study of specific sig naling and membrane transport events in living cells. In this review, we highlight the close ties between endocytosis and signaling by discussing important observations from early studies along with selected recent studies that have provocative implications. 2 Endocytosis of Signaling Receptor The most comprehensive studies of RTK endocytosis have been carried out with the epidermal growth factor (EGF) receptor as a model system (Fig. 1). Cellular stimulation with EGF results in rapid clustering of EGF receptor complexes in clathrin-coated pits and the subsequent in ternalization into clathrin-coated endocytic vesicles (Gorden et al. 1978; Receptor Tyrosine Kinase Signaling and Trafficking-Paradigms Revisited 3 Recydm, Endosome olgi ompl . Fig. 1. Endocytic pathway: This figure shows the progression of an endocytic vesicle from internalization to maturation at the lysosome. RTKs are used to illustrate the possible fates of an endocytosed receptor complex. The various Rab GTPases thought to be involved in this pathway are also indicated. Rab22 may playa role in membrane sorting in the early endosome (Mesa et al. 2001) Hanover et al. 1984; Carpentier et al. 1982). The internalization of EGF receptors can be effectively blocked by dominant-negative mutants of several regulatory proteins. Examples include dynamin, a cytoplasmic GTPase that is necessary for the fission of coated vesicles from the plas ma membrane, and Rab5, a cytoplasmic GTPase that is necessary for en dosome fusion (Barbieri et al. 2000; Damke et al. 1994; Carbone et al. 1997). Under physiological conditions, coated pits are the main routes for internalization of growth factor receptors. However, these receptors have also been shown to internalize by clathrin-independent processes that resemble micropinocytosis, particularly in cells over expressing the receptor (Haigler et al. 1979; Hopkins et al. 1985).