Integrins and Ion Channels (eBook)

ANDREA BECCHETTI, PhD, is Professor of General, Comparative and Cellular Physiology at the Department of Biotechnology and Biosciences of the University of Milano-Bicocca, Italy. After receiving his academic degrees at the University of Milan, he has spent prolonged research sojourns at the Department of General Pathology of the University of Florence, Italy, the Department of Physiology at Emory University in Atlanta, Georgia, USA, the Department of Physiological Sciences of the University of Newcastle upon Tyne, UK, and the Biophysics Sector of the International School for Advanced Studies (ISAS-SISSA), in Trieste, Italy.His current research interests include the role of ion channels in cell adhesion and proliferation, the nicotinic modulation of synaptic transmission in the mammalian cerebral cortex and the pathogenesis of sleep-related epileptic forms linked to mutant human nicotinic receptors. Andrea Becchetti is member of the Society of General Physiologists, Biophysical Society, Society for Neuroscience and the Italian Physiological Society. ANNAROSA ARCANGELI, MD, PhD is Professor of General Pathology and Immunology at the Department of Experimental Pathology and Oncology of the University of Firenze (Florence, Italy). She is the Scientific Director of the Laboratory of Genetic Engineering for the Production of Animal Models of the University of Firenze. After receiving her MD degree at the University of Firenze, she spent several research sojourns at the Department of Physiology of the University of Milano, at the Institut d’Embriologie Cellulaire et Moleculaire, Nogent sur Marne, Paris, France and at the MRC-LMB Centre of Cambridge, UK. Her main research interests include the role of ion channels, in particular potassium channels, in the regulation of different aspects of tumor cell behaviour, including the cross talk with adhesion receptors, as well as the identification of ion channels as novel targets for cancer therapy. Annarosa Arcangeli is member of the Italian Society of Pathology, the Association of Cell Biology and Differentiation (ABCD), the American Society of Hematology.

PREFACE 6
ABOUT THE EDITORS... 9
ABOUT THE EDITORS... 10
PARTICIPANTS 11
Table of Contents 14
ACKNOWLEDGEMENTS 17
Chapter 1Integrin Structure and FunctionalRelation with Ion Channels 18
Introduction 18
Fundamentals of Integrin Structure 19
Extracellular Domains and ECM Ligand Binding 19
Transmembrane and Intracellular Domains 20
TM Domain Interaction 20
Inside-Out Activation by Talin 21
Binding to Other Membrane Proteins and Cytoskeleton 22
Physiological and Pathological Implications: An Outline of Current Trends 22
Conclusion 23
References 23
Chapter 2 Introduction to Ion Channels 25
Introduction 25
The Physiology of Ion Channels 26
Biophysical Background 26
Main Physiological Roles of Ion Channels 27
Ion Channel Types Involved in Integrin-Mediated Signaling 29
Voltage-Gated K+ Channels 29
Inward Rectifying K+ Channels 31
Ca2+ -Activated K+ Channels 31
Voltage-Gated Ca2+ Channels 33
Cl- Channels 33
Neurotran smitter-Gated Channels 34
Conclusion 35
References 35
Chapter 3 Biochemical Methods to Studythe Interactions Between Integrinsand Ion Channels 38
Introduction 39
Yeast Two-Hybrid Screening 39
Affinity-Based Screening: IP Assays 41
Pull-Down Assay 42
Photoaffinity Labeling Techniques for Studying Transient Protein-Protein Interaction 43
Far Western Blot Analysis (Far WB) 44
High-Throughput Protein-Protein Interaction Analysis, Followed by Validation of Candidate Interactors through Different Experimental Approaches 44
Conclusion: Past and Future Application of Biochemical Approaches to Characterize the Interactions between Integrins and Ion Channels 45
References 46
Chapter 4 Optical Methods in the Studyof Protein-Protein Interactions 48
Introduction 49
Förster Resonance Energy Transfer: The “Molecular Ruler” 49
Intensity Versus Lifetime: Two Ways to Measure FRET 51
Total Internal Reflection Fluorescence Microscopy (TIRFM) and Imaging of Membrane Proteins 53
Antibody-Based Versus Fusion Protein-Based FRET: Principles 53
Antibody-Based Versus Fusion Protein-Based FRET: Advantages and Disadvantages 54
Application of Optical Methods to the Study of Integrins and Ion Channels 55
Conclusion 56
References 56
Chapter 5 Integrins and Signal Transduction 58
Overview of Integrin Structure 58
Structural Features of the Integrin Family 58
Connection between the ECM and the Actin Cytoskeleton 58
Integrin Signaling 61
The SFK-Fak-p130Cas Signaling 61
The Focal Adhesion Kinase 62
Src Family Kinases 62
The p130Cas Adaptor Protein 62
SFK-Fak-p130Cas as a Signaling Scaffold in Migration, Invasion and Survival 63
Integrin Cross Talk with Growth Factor and Cytokine Receptors 63
Cooperation between Integrins, Growth Factor/Cytokine Receptors and Their Ligands: Reciprocal Potentiation 64
Integrin Signaling and Cancer 66
Conclusion 67
References 67
Chapter 6 Physical and Functional Interaction between Integrins and hERG1 Channels in Cancer Cells 70
Introduction 71
hERG1 Channels in Cancer Cells 71
Effects of Integrin Activation on hERG1 Channels 74
Integrins and hERG1 Channels form a Macromolecular Complex 76
Effects of hERG1 Activation on Integrin Function and Signaling 77
Conclusion 79
References 80
Chapter 7 Coordinated Regulation of Vascular Ca2+and K+ Channels by Integrin Signaling 83
Introduction 83
Regulation of L-Type Calcium Channels by Integrin Activation 84
Regulation of Ca2+-Dependent Potassium Channels by Integrin Activation 87
Conclusion: The Physiological Relevance of Coordinated Regulation of CaL and BK Channels by Integrins 90
References 91
Chapter 8 Adhesion-Dependent Modulationof Macrophage K+ Channels 94
Introduction 94
Inwardly Rectifying K+ (Kir) Currents 94
Physiologic and Pathophysiologic Roles of Macrophage Kir Channels 100
Delayed, Outwardly Rectifying K+ (Kdr) Currents 101
Physiologic and Pathophysiologic Roles of Macrophage Kdr Channels 102
Conclusion 105
References 105
Chapter 9 Integrin Receptors and Ligand-GatedChannels 108
Introduction 108
The Functional Significance of Integrins in the Adult Brain 109
Integrin and Ion Channels in Remodeling Adult Circuits and Epileptogenesis 111
Integrins and Synaptic Plasticity 111
Integrins and NMDA Receptors 112
Integrins and AMPA Receptors 112
Integrins and GABA Receptors: Further Possibilities to Modulate Synaptic Plasticity? 113
Integrins and Nicotinic Acetylcholine Receptors: Not Only the Neuromuscular Junction 113
Studies in Nonneural Tissue 113
Studies in the Neuromuscular Junction and the Central Nervous System 115
Conclusion 115
References 116
Chapter 10 Integrins and Ion Channels in CellMigration:Implications for Neuronal Development, WoundHealing and Metastatic Spread 119
Introduction 120
Actin Cytoskeleton 120
Cell Migration 121
Growth Cone Motility 121
The Role of Integrins in Cell Migration 122
The Role of Ion Channels and Crosstalk with Integrins in Cell Migration 123
K+ Channels 123
Nicotinic Acetylcholine Receptors, Integrins and Epithelial Migration in Electric Fields, Implications for Wound Healing 124
Ca2+ Signaling and the Axonal Growth Cone 125
Ca2+ Signals: Fundamentals and Role in Chemotaxis 125
Growth Cone Motility 125
Ion Channels as Adhesion Molecules 127
The Cellular Environment and the Metastatic Process 127
Invasiveness of Glial Tumors and Ion Channels 130
Conclusion 130
References 131
INDEX 136