GTPases in Biology II

Contributors

M. Biel, L. Birnbaumer, K.J. Blumer, J. Bockaert, E. Bosse,J.L. Boyer, P. Brabet, M. Camps, M.G. Caron, P.J. Casey, J. Chen,K. Clark, D. Corda, S. Coulter, P.N. Devreotes, D. Donelly,T.D. DuBose, Jr., J.H. Exton, J.B.C. Findlay, R.A. Firtel,V. Flockerzi, M. Forte, C. Gaskins, P. Gierschik, R. Gundersen,R.W. Gurich, J.R. Hadcock, J.A. Hadwiger, T.K. Harden,J.D. Hildebrandt, Y.-K. Ho, F. Hofmann, K.P. Hofmann,V. Homburger, M.D. Houslay, R. Hullin, D. Hyde, R. Iyengar,O. Jacobowitz, S. Jahangeer, K.H. Jakobs, G.L. Johnson,R.L. Johnson, N. Kimura, S.D. Kroll, Y. Kurachi, R.H. Lee,R.J. Lefkowitz, Y. Li, C. Londos, C.C. Malbon, D.H. Maurice,K.R. McLeish, G. Milligan, A.J. Morris, E.J. Neer, A.S. Otero,U. Panten, D. Park, G.S. Pitt, R.T. Premont, F. Quan, M. Rodbell,W. Rosenthal, M. Russell, P. Ruth, C. Schwanstecher,M. Schwanstecher, LA. Simpson, E. Stefani, G. Szabo,J.A. Thissen, T.D. Ting, L. Toro, G.L. Waldo, A. Welling,T.G. Wensel, M. Whiteway, W. Wolfgang, L. Wu

Editors

Burton F. Dickey and Lutz Birnbaumer

onr

Springer-VerlagBerlin Heidelberg New York London ParisTokyo Hong Kong Barcelona Budapest

Contents

Section IV: Signal Transduction by Trimeric G ProteinsA. Cellular Architecture and its Role in Signal Transduction

CHAPTER 44

G-Proteins Have Properties of Multimeric Proteins: An Explanationfor the Role of GTPases in their Dynamic BehaviorM. RODBELL, S. JAHANGEER, and S. COULTER. With 2 Figures 3

A. Introduction 3B. Theories 4

I. Shuttle Theory 4II. Collision-coupling Theory 4

HI. Disaggregation Theory 5C. Evidence for Multimeric Structures of G-Proteins 5

I. Properties in Detergents 5II. Cross-Linking of G-Proteins in Membranes 6

III. Glucagon Activation of Multimeric Gs in HepaticMembranes 7

D. Coupling of Receptors to Multimeric G-Proteins 8E. Hydrolysis of GTP Is Fundamental to Signal Transduction

Dynamics 9F. Conclusions 11References 12

B. G-Protein Coupled Receptors

CHAPTER 45

The Superfamily: Molecular ModellingJ .B.C. FINDLAY and D . DONNELLY. With 4 Figures 17

A. Introduction 17B. General Principles - Modelling Integral Membrane Domains . . . . 18

XVI Contents

I. Summary of Information Available for G-Protein-CoupledReceptor Modelling Studies 20

C. Modelling G-Protein-Coupled Receptors from SequenceAlignments 21

I. Sequence Comparisons 21II. Fourier Transform Analysis of G-Protein-Coupled Receptor

Sequence Alignments 211. Prediction of Structural Environments from Sequence

Alignments 212. Detection of Periodicity and the Discrimination of the

Different Sides of the Helix 223. Detection of the Ends of the Transmembrane Regions of

the Helices 234. Summary of Methodology 235. Application to G-Protein-Coupled Receptors 24

D. Three-Dimensional Models of G-Protein-Coupled Receptors . . . . 27I. Construction of G-Protein-Coupled Receptor Models Based

on the Fourier Transform Predictions 27II. Analysis of the Models 28

References 30

CHAPTER 46

The Role of Receptor Kinases and Arrestin-Like Proteinsin G-Protein-Linked Receptor DesensitizationR.J. LEFKOWITZ and M.G. CARON. With 6 Figures 33

References 41

C. Trimeric G-Proteins

CHAPTER 47

Qualitative and Quantitative Characterization of the Distribution ofG-Protein a Subunits in MammalsG. MILLIGAN. With 4 Figures 45

A. Introduction 45B. Identification of G-Protein a Subunits 46

I. [32P]ADP Ribosylation 46II. Immunological Determination of G-Protein Distribution . . . . 53

C. Immunological Determination of G-Protein a Subunit Levels . . . . 55I. Quantitative and Relative Intensity Immunoblotting 55

II. ELISA 58III. Other Approaches 58

Contents XVII

D. Asymmetric Distribution of G-Proteins inthe Plasma Membrane 59

E. Conclusions 60References 60

CHAPTER 48

Subunit Interactions of Heterotrimeric G-ProteinsE.J. NEER. With 3 Figures 65

A. Signalling by a and fly Subunits 65I. Effect of Subunit Association on the Guanine Nucleotide

Binding and GTPase Activity 66II. Physical Properties of Associated and Dissociated G-Protein

Subunits 67III. The a and fly Interface 68

1. Analysis by Site-Directed Mutagenesis of Requirmentsfor a and fly Interactions 68

2. Analysis of afl Contact Regions by Cross-Linking 703. Probing the a and jiy Interface with Antibodies 72

IV. Does Dissociation of a and fly Occur in the PlasmaMembrane? 73

B. Interaction of fl and y Subunits 73I. Site of Interaction of flx with y1 and y2 74

C. Specificity of Interaction Between Particular a and flyCombinations 74

References 75

CHAPTER 49

G-Protein a Subunit Chimeras Reveal Specific Regulatory DomainsEncoded in the Primary SequenceM. RUSSELL and G.L. JOHNSON. With 5 Figures 79

A. Background 79B. Mutational Analysis of the GDP/GTP Binding Domain 80C. Competitive Inhibitory Mutations 84D. Regulatory Properties of the as N Terminus 85E. ai2/as Chimeras Reveal the Regulatory Function of

the a Subunit N Terminus 86F. Mutations that Influence GDP Dissociation and GTPase

Activity Create Strong Constitutively Active as Polypeptides . . . . 88G. Sites of fly Subunit Interactions 90H. Mapping of the as Adenylyl Cyclase Activation Domain 92I. Conclusions 93References 95

XVIII Contents

CHAPTER 50

The GTPase Cycle: TransducinT.D. TING, R.H. LEE, and Y.-K. Ho. With 6 Figures 99

A. The Retinal cGMP Cascade and Visual Excitation 99B. The Coupling Cycle of Transducin 100C. The Reaction Dynamics of the Transducin Cycle 102

I. Transducin Subunit Interaction 102II. Pre-Steady-State Kinetic Analysis of the GTP Hydrolysis

Reaction 104III. Quantitative Analysis of the Pre-Steady-State Kinetics 107

D. Relationship of GTP Hydrolysis and PDE Deactivation 110E. Regulation of the Transducin Coupling Cycle by Phosducin 113F. Concluding Remarks 115References 115

CHAPTER 51

Transcriptional, Posttranscriptional, and PosttranslationalRegulation of G-Proteins and Adrenergic ReceptorsJ.R. HADCOCK and C.C. MALBON. With 2 Figures 119

A. Introduction 119B. Agonist-Induced Regulation of Transmembrane Signaling 120

I. Transcriptional and Posttranscriptional Regulation 120II. Posttranslational Regulation 123

C. Cross-Regulation in Transmembrane Signaling 123I. Stimulatory to Inhibitory Adenylyl Cyclase 123

II. Inhibitory to Stimulatory Adenylyl Cyclase 124III. Stimulatory Adenylyl Cyclase to Phospholipase C 125IV. Tyrosine Kinase to Stimulatory Adenylyl Cyclase 126

D. Permissive Hormone Regulation of Transmembrane Signaling . . . 126E. Perspectives 127References 128

CHAPTER 52

G-Protein Subunit Lipidation in Membrane Association and SignalingJ.A. THISSEN and P.J. CASEY. With 4 Figures 131

A. Introduction 131B. Myristoylation and Membrane Association of G-Protein a

Subunits 133I. Cotranslational Processing of G-Protein a Subunits 133

II. The Role of Myristoylation in a Subunit-MembraneAssociation 135

Contents XIX

C. Prenylation and Membrane Association of G-Protein y Subunits 138I. Posttranslational Processing of G-Protein y Subunits 138

II. The Role of Prenylation in y Subunit-MembraneAssociation 1391. Geranylgeranyl-Modified y Subunits 1402. Farnesyl-Modified y Subunits 142

D. Future Directions 142References 143

CHAPTER 53

Phosphorylation of Heterotrimeric G-ProteinM.D. HOUSLAY. With 1 Figure 147

A. Introduction 147I. Nature of G-Proteins 147

II. Modulation of G-Protein Action 1481. Phosphorylation 149

B. Phosphorylation of Heterotrimeric G-proteins in Intact Cells . . . . 150I. Hepatocytes 150

II. Promonocytic Cell Line U937 154III. Platelets 155

1. G r 2 1552. Gz 155

IV. Yeast 156V. Dictyostelium 157

C. In Vitro Phosphorylation of Isolated Heterotrimeric G-Proteins . . 158I. Transducin 158

II. Gi and Go 158ffl. Gs 160IV. Unidentified "G-Proteins" 161

D. Conclusion 162References 162

CHAPTER 54

Receptor to Effector Signaling Through G-Proteins:fiy Dimers Join a Subunits in the World of Higher EukaryotesL. BIRNBAUMER. With 6 Figures 167

A. Introduction 167B. fly Dimers and Adenylyl Cyclase 168

I. Hormonal Inhibition of Adenylyl Cyclase and Stimulation ofK+ Channels: Controversies that Settled Mostly in Favor ofa Subunits 168

XX Contents

II. Conditional and Subtype-Specific Regulation of AdenylylCyclase Activity by fly Dimers 169

C. fly Dimers and Phospholipase C: Subtype-Specific Stimulation ofType fl Phospholipase C by fly Dimers 171

D. fly Dimers and Receptors: Exquisite Specificity of Receptors forfly Subtypes 172

E. Dual Signaling of Single Receptors: Mediation by One orby Two G-Proteins? 174

I. Inhibition of Adenylyl Cyclase and Stimulation ofPhospholipase C 174

II. Signaling Quality Through Receptor Quantity? 175III. Dual Stimulation of Adenylyl Cyclase

and Phospholipase C 176IV. Evidence for Physical Interaction of a Single Receptor with

Two Distinct Types of G-Proteins 178F. The Puzzle of the Up-Shifted Dose-Response Curves for

Phospholipase C Elicited by Adenylyl Cyclase StimulatingAgonists 179

G. Concluding Remarks 180References 181

D. Effectors of G-Proteins

CHAPTER 55

Molecular Diversity of Mammalian Adenylyl Cyclases:Functional ConsequencesR.T. PREMONT, J. CHEN, O. JACOBOWITZ, and R. IYENGAR.

With 5 Figures : 189

A. Introduction 189B. Stimulation and Inhibition of Adenylyl Cyclases 190C. Molecular Diversity of Adenylyl Cyclases 193

I. Multiple Families of Adenylyl Cyclases 193II. Secondary Structure and Topography 196

III. Putative Catalytic Sites 198IV. Tissue Distribution of the Various Forms 199

D. G-Protein Regulation of Adenylyl Cyclases 201I. Gs-a Regulation 201

II. Gj-ct Regulation 201III. fly Regulation 201

E. Type-Specific Regulation by Intracellular Ligands 202I. Ca2+/CaM Regulation 202

II. Inhibition by Low Concentrations of Ca2+ 202III. P-Site Inhibition 204

Contents XXI

F. Regulation by Protein Phosphorylation 204I. Regulation by Protein Kinase C 204

II. Protein Kinase A Regulation: A Component ofHeterologous Desensitization 205

G. Functional Consequences of Multiple Adenylyl Cyclases 206I. Integration of Multiple Signals 206

II. Modulation of Signal Transmission 207References 208

CHAPTER 56

The Light-Regulated cGMP Phosphodiesterase of VertebratePhotoreceptors: Structure and Mechanism of Activation by GtaT.G. WENSEL. With 2 Figures 213

A. Physiological Role of cGMP Phosphodiesterase in VisualSignaling 213

B. Structure 213I. Subunit Composition 213

II. Size and Hydrodynamic Properties 214III. Primary Structure 214IV. Posttranslational Modifications 214V. Domain Structures of Subunits 215

1. Catalytic Subunits 2152. Inhibitory Subunit 215

C. Functional Properties 216I. Solubility 216

II. Kinetic Properties 216III. Noncatalytic cGMP Binding Sites 216

D. Regulation of Catalytic Activity 217I. Inhibition by PDEy 217

II. Activation by G-Protein 2181. Role of Gta 2182. Role of Membranes in PDE Activation by Gta 2183. Role of PDEy in Activation by Transducin 2184. Is There Cooperativity in the Action of Gta-GTP? 2195. A Role for Noncatalytic cGMP Binding Sites? 220

References 220

CHAPTER 57

High-Voltage Activated Ca2+ ChannelF. HOFMANN, M. BIEL, E. BOSSE, R. HULLIN, P. RUTH, A. WELLING,and V. FLOCKERZI. With 1 Figure 225

A. Introduction 225

XXII Contents

B. Identified cDNAs of High-Voltage ActivatedCalcium Channels 225

I. The ax Subunit 227II. The a2/S Subunit 228

III. The fl Subunit 229IV. The y Subunit 229

C. Structure-Function of the Cloned Calcium Channel Proteins 229I. Expression and Function of the Channel Subunits 229

II. The Binding Sites for Calcium Channel Blockers 232III. Phosphorylation of the Channel Proteins 233

D. Conclusion 234References 234

CHAPTER 58

Phospholipase C-fi Isozymes Activated by Gaq MembersD. PARK. With 3 Figures 239

References 248

CHAPTER 59

Stimulation of Phospholipase C by G-Protein fly SubunitsP. GIERSCHIK and M. CAMPS. With 4 Figures 251

A. Introduction 251B. Stimulation of Soluble Phospholipase C of HL-60 Granulocytes

by G-Protein fly Subunits 252C. Identification of the /fy-Sensitive Phospholipase C of HL-60

Granulocytes as PLC/?2 254D. Stimulation of PLQ?2 by G-Protein fly Subunits in Intact Cells . . . 256E. Role of fly Subunits in Mediating Receptor Stimulation of

Phospholipase C 257F. Perspectives 259References 260

E. Specialized Systems

CHAPTER 60

Rhodopsin/G-Protein InteractionK.P. HOFMANN. With 7 Figures : 267

A. Introduction 267B. Interactions of Rhodopsin in the Visual Cascade 267C. Biophysical Monitors of G-Protein Activation 270

Contents XXIII

I. Description of the Monitors 270II. Instrumentation 271

III. Application to the Analysis of R*-Gt Interaction 273IV. Preparations 276

D. Interactive States of Rhodopsin 277I. Molecular Nature of Metarhodopsin II 277

II. Active Forms of Rhodopsin from Alternative Light-InducedPathways 278

III. Activation of Rhodopsin in the Dark 278E. Interactive States of Transducin 279

I. Dark Binding 279II. Stable Light Binding with Empty Nucleotide Site 279

III. Rhodopsin/G-Protein Interaction with Bound Nucleotides . . 280F. Mechanism of Transducin Activation 280

I. Role of Rhodopsin's Cytoplasmic Loops 2801. Three Loops Contribute to MII-G, Interaction 2802. Loop Mutants: Binding and Activation in MII-G,

Interaction 283II. Dissection of Reaction Steps 283

1. The GDP/MII Switch 2832. The MH/GTP Switch 284

III. Regulation of the Activation Pathway 286G. Conclusion 286References 287

CHAPTER 61

Fast Kinetics of G-Protein Function In VivoG. SZABO, Y. Li, and A.S. OTERO. With 6 Figures 291

A. Introduction 291B. Kinetics of Muscarinic K+ Channel Activation 291C. Rapid Desensitization 295D. Kinetics of IK(AOI) Deactivation 298E. Basic Kinetic Model for Membrane-Delimited Effector

Activation by a G-Protein 299F. Conclusions 300References 301

CHAPTER 62

The Yeast Pheromone Response G-ProteinK. CLARK and M. WHITEWAY. With 3 Figures 303

A. Introduction 303B. Overview 304

XXIV Contents

C. Gpal, the Get Subunit 305I. Random Mutagenesis 306

II. Site-Directed Mutagenesis 307D. Ste4, the Gfl Subunit 309

I. Random Mutagenesis 309II. Site-Directed Mutagenesis 312

E. Stel8, the Gy Subunit 312I. Random Mutagenesis 313

II. Site-Directed Mutagenesis 314F. Conclusions 315References 315

CHAPTER 63

Ga Proteins in Drosophila: Structure and Developmental ExpressionM. FORTE, F. QUAN, D. HYDE, and W. WOLFGANG. With 3 Figures. . . 319

A. Introduction 319I. G-Protein-Coupled Signaling in Development 319

II. The Drosophila System 319B. Ga-Proteins in Drosophila 322

I. DGsa 3221. Gene Structure 3222. Adult and Embryonic Expression 3243. Stimulation of Mammalian Adenylyl Cyclase Through

DGsa 324II. DGoa 325

1. Gene Structure 3252. Adult and Embryonic Expression 325

III. DG ia 3271. Gene Structure 3272. Adult and Embryonic Expression 327

IV. DGqa 3281. Gene Structure 3282. Adult Expression 3293. Role in Phototransduction 329

V. concertina 3311. Mutant Phenotype 3312. Cloning and Gene Structure 3313. Expression of eta 332

C. Summary 332References 333

CHAPTER 64

Signal Transduction by G-Proteins in Dictyostelium discoideumL. Wu, C. GASKINS, R. GUNDERSEN, J.A. HADWIGER, R.L. JOHNSON,

G.S. PITT, R.A. FIRTEL, and P.N. DEVREOTES. With 8 Figures 335

Contents XXV

A. Introduction 335B. Signal Transduction in Dictyostelium 335C. Diversity of G-Proteins in Dictyostelium 337D. Roles of G-Proteins in Signal Transduction Processes 340E. Roles of G-Proteins in Morphogenesis and Differentiation 345F. Conclusions and Perspectives 347References 348

CHAPTER 65

Functional Expression of Mammalian Receptors and G-Proteinsin YeastK.J. BLUMER. With 1 Figure 351

A. Introduction 351B. Expression of Mammalian G-Protein-Coupled Receptors 352C. Expression of Mammalian G-Protein Subunits 357

I. Physiological Roles of Yeast G-Protein Subunits 357II. Mammalian Ga Subunits 357

1. Intact Ga Subunits 3572. Chimeric Yeast/Mammalian Ga Subunits 358

III. Mammalian Gp and Gy Subunits 359D. Signaling Between Mammalian Receptors and G-Proteins 359E. Perspectives 359References 360

CHAPTER 66

G-Proteins in the Signal Transduction of the NeutrophilK.R. MCLEISH and K.H. JAKOBS 363

A. Introduction 363B. Receptor-Mediated PMN Functions 363

I. Adherence 363II. Chemotaxis 364

III. Phagocytosis and Bactericidal Activity 364IV. Regulatory Receptors 364

C. G-Protein-Coupled Receptors 364I. Chemoattractant Receptors 365

II. Purinergic Receptors 368III. Other PMN Receptors 369

D. Regulation of Neutrophil Responses 369I. Priming 369

II. Desensitization 370References 370

XXVI Contents

CHAPTER 67

Hormonal Regulation of Phospholipid Metabolism via G-Proteins:Phosphoinositide Phospholipase C and PhosphatidylcholinePhospholipase DJ.H. EXTON 375

A. Introduction 375B. Identification of the G-Proteins Regulating PtdInsP2

Phospholipase C 375C. Coupling of G-Proteins to Ca2+-Mobilizing Receptors 377D. Specificity of Phosphoinositide Phospholipase C Linked to Gq

and G n 379E. Mechanisms of Agonist-Stimulated Phosphatidylcholine

Breakdown 380F. Summary 381References 381

CHAPTER 68

Hormonal Regulation of Phospholipid Metabolism via G-proteins II:PLA2 and Inhibitory Regulation of PLCD. CORDA. With 2 Figures 387

A. Introduction 387B. Modulation of PLA2 387

I. Molecular Forms of PLA2 388II. G-Protein-Mediated Activation of PLA2 388

III. Molecular Aspects 390IV. Inhibitory Regulation of PLA2 , 391

C. Activity of PLA2 in ras-Transformed Cells 392D. Inhibitory Regulation of PLC 393

I. Molecular Aspects 395E. Conclusion 396References 396

CHAPTER 69

G-Protein Regulation of Phospholipase C in the Turkey ErythrocyteA.J. MORRIS, D.H. MAURICE, G.L. WALDO, J.L. BOYER,

and T.K. HARDEN 401

A. Introduction 401B. Properties of P2Y Purinergic Receptor and G-Protein-Regulated

PLC in Turkey Erythrocytes 403I. Initial Observations 403

II. Kinetics of Activation of PLC by P2Y Purinergic ReceptorAgonists and Guanine Nucleotides 404

Contents XXVII

C. Identification, Purification, and Primary Structure of the ProteinComponents of the Turkey Erythrocyte Inositol Lipid-DependentSignaling System 405I. G-Protein-Regulated PLC ; 405

1. Purification and Properties of a G-Protein-Regulated PLCfrom Turkey Erythrocytes 406

2. Receptor and G-Protein Regulation of the PurifiedTurkey Erythrocyte PLC 407

II. G-Protein Activators of PLC 4081. Purification and Properties of the Turkey Erythrocyte

PLC-Activating G-Protein 4102. cDNA Sequence of the Turkey Erythrocyte PLC-

Activating G-Protein and its Relationship to MammalianG-Protein a Subunits 410

D. Concluding Comments 411References 412

CHAPTER 70

Hormonal Inhibition of Adenylyl Cyclase by atand fly, ctj or fly, at and/or fiyJ.D. HILDEBRANDT. With 2 Figures 417

A. Introduction 417B. Mechanism(s) Mediating Inhibition of Adenylyl Cyclase 418

I. Direct Inhibition of Adenylyl Cyclase by a ; . , 418II. Indirect Inhibition of Adenylyl Cyclase by fly Suppression of

as Activation 419III. Direct Inhibition of Adenylyl Cyclase by fly 420

C. Current View of Inhibition of Adenylyl Cyclase 421I. The Mechanism of Inhibition of Adenylyl Cyclase in S49

Cells 422II. Significance and Predications of Multiple Mechanism for

Inhibition 424III. Unresolved Structural and Functional Issues about

G-proteins Affecting the Mechanism(s) MediatingHormone Inhibition of Adenylyl Cyclase 425

D. Conclusion 426References 426

CHAPTER 71

Neurobiology of GoP. BRABET, V. HOMBURGER, and J. BOCKAERT. With 3 Figures 429

A. Introduction 429

XXVIII Contents

B. Gene Structure of Goa in Vertebrates and Invertebrates 429I. Gene Structure and Transcription in Vertebrates 429

II. Gene Structure and Transcription in Invertebrates 430C. Cellular Expression of Go in Excitable Cells and Its Regulation .. 432

I. Cellular and Subcellular Distribution 4321. Neurons 4322. Nonneuronal Cells 434

II. Control of Go, Gol, and Go2 Expression During NeuronalDifferentiation 435

D. Neurotransmitter Receptors Coupled to Go and Their InhibitoryEffects on Voltage-Sensitive Ca2+ Channels 436

I. Nature of Receptors 4361. Reconstitution of Resolved Receptors and G0-Proteins... 4362. Reconstitution of Receptor Coupling to VSCC with Go-

Protein in PTX-Treated Cells 4363. Stimulation of Go Photolabeling with [a-

32P]GTPAzidoanilide by Neurotransmitters 438

4. Intracellular Injections of G-protein Antibodies and ofAntisense Oligonucleotides Complementary to G-Proteinor DNA Sequences To Demonstrate the Specificity ofthe Negative Coupling Between Receptors and VSCCvia Go 438

5. Immunoprecipitation of Receptor-GQ Complexes withAnti-Go Antibodies and Anti-receptor Antibodies 440

II. Nature of VSCC Inhibited by Go 440III. Colocalization of Go and L-Type VSCC in T-Tubule 440IV. Conclusions 441

E. General Conclusion 441References 441

CHAPTER 72

Involvement of Pertussis-Toxin-Sensitive G-Proteins in the Modulation ofCa2+ Channels by Hormones and NeurotransmittersW. ROSENTHAL. With 1 Figure 447

A. Introduction 447B. Inhibitory Modulation of Voltage-Dependent Ca2 + Channels . . . . 447

I. Occurrence; Physiological Significance 447II. Effects of Receptor Agonists, Pertussis Toxin, and Guanine

Nucleotides 449III. Types of Ca2+ Channels Affected by Inhibitory Receptor

Agonists 450IV. Mechanistic Aspects 452

1. Cyclic Nucleotides 452

Contents XXIX

2. Protein Kinase C and Fatty Acids 4533. Evidence for a Membrane-Delimited Pathway 454

V. Identification of the Involved G-Protein 4541. Occurrence of Go 4542. Reconstitution Experiments with Native and

Recombinant G-Proteins; Transfected Cells 4553. Antibodies 4564. Go-Activating Receptors 4565. Antisense Oligonucleotides 457

C. Stimulatory Modulation of Voltage-Dependent Ca2+ Channels .. 458I. Occurrence; Physiological Significance 458

II. Effects of Pertussis Toxin and Guanine Nucleotides 459III. Types of Ca2+ Currents Affected by Stimulatory Receptor

Agonists 460IV. Mechanistic Aspects 460V. Identity of the G-Protein Involved 461

D. Conclusion 462References 463

CHAPTER 73

Regulation of Cell Growth and Proliferation by GoS.D. KROLL and R. IYENGAR. With 3 Figures 471

A. Introduction 471B. The Go-Protein 471C. The Go-Protein and Cell Cycle Regulation in the Xenopus

Oocyte 473D. Regulation of Oocyte Maturation by Multiple Pathways 477E. Proliferation of Mammalian Cells by Activated Go 478F. Specificity of Transformation by Signaling Through

G-Protein Pathways 479G. Desensitization and Growth Signaling Through

G-Protein Pathways 481References 481

CHAPTER 74

Role of Nucleoside Diphosphate Kinase in G-Protein ActionN. KIMURA. With 6 Figures 485

A. Introduction 485B. General Model of Membrane Signaling Systems Involving

G-Proteins 485C. Role of NDP Kinase in Membrane Signaling Systems 486

I. Evaluation of the Effect of GDP in Comparison with GTP .. 486

XXX Contents

II. Role of mNDP Kinase in Signal Transduction 487III. Comparison Between Hormone and Cholera Toxin Actions 490IV. Interaction Between mNDP Kinase and Gs, and Its

Regulation 490V. Regulatory Mechanism of G-Protein by NDP Kinase 491

VI. Physiological Relevance of G-Protein Regulation by mNDPKinase 494

D. Properties of NDP Kinases and Their Structure 495E. Novel Roles of NDP Kinases in Cellular Functions 495F. Concluding Remarks 496References 496

CHAPTER 75

G-Protein Regulation of Cardiac K+ ChannelsY. KURACHI. With 16 Figures 499

A. Introduction 499B. Involvement of G-Protein in Muscarinic Activation of the KACh

Channel 499C. Physiological Mode of G-Protein Activation of the K A a ,

Channel 502D. Effects of G-Protein Subunits on the Cardiac KACh Channel 504

I. Comparison Between the Regulation of Adenylyl CyclaseActivity and the KACh Channel Activity by PurifiedG-Protein Subunits ; 506

II. Effects of Gpy on the KACh Channel 5071. Voltage-Dependent Properties of the G^-Activated KACh

Channel 5072. Concentration Dependence of Gpy Activation of the KACh

Channel 5093. Specificitiy of Gp7 Activation of the KACh Channel 5104. Gpy Activation of the KACh Channel Is Not Mediated by

Phospholipase A2 5115. Antibody 4A Does Not Inhibit the Interaction Between

GK and the KACh Channel 512III. Effects of G-Protein on the ATP-Sensitive K Channel 514

E. Stimulatory Modulation of the GK-Gated Cardiac KACh Channel 515I. Arachidonic Acid and Its Metabolites 515

II. Phosphorylation 520III. NDP-Kinase 521IV. Intracellular Chloride 522

F. Conclusion 523References 523

Contents XXXI

CHAPTER 76

Modulation of K+ Channels by G-ProteinsL. BIRNBAUMER. With 9 Figures 527

A. Direct Regulation of Ionic Channels by G-Proteins 527I. The Inwardly Rectifying "Muscarinic" K+ Channel 527

1. Experiments Leading to the Discovery of G-ProteinGating 527

2. Direct Stimulation by hRBC G, and Its a Subunit 5293. Properties of the Grstimulated K

+ Channel 5324. Identity of the Gk that Gates the Muscarinic-Type K

+

Channels 534II. The ATP-Sensitive K+ Channel: A Second G rGated K

+

Channel 5361. General Properties of the ATP-Sensitive K+ Channel/

Sulfonyliurea Receptor Complex 5362. Identity of G-proteins that Regulate the ATP-Sensitive

K+ Channel 537III. G-Protein Gating as a Tool To Discover Novel Ionic

Channels: Neuronal Go-Gated K+ Channels 539

B. Effect of fly Dimers: Inhibition versus Stimulation of theMuscarinic K+ Channel - A Persisting Controversy 541

C. Conclusions 543References 544

CHAPTER 77

ATP-Sensitive K+ Channel: Properties, Occurrence, Role inRegulation of Insulin SecretionU. PANTEN, C. SCHWANSTECHER, and M. SCHWANSTECHER.

With 2 Figures 547

A. Introduction 547B. Biophysical Properties 547C. Regulation of the KATP Channel 548

I. Inhibition by Intracellular Nucleotides 548II. Activation by Intracellular Nucleoside Diphosphates 549

III. Activation by Intracellular MgATP 550IV. Activation by G-Proteins 550V. Inhibition by G-Proteins 551

VI. Inhibition by Drugs 551VII. Activation by Drugs 552

VIII. Characteristics of the Sulfonylurea Receptor 552

XXXII Contents

D. Role of the KATP_ Channel in Regulation of Insulin Secretion . . . 553References 555

CHAPTER 78

Modulation of Maxi-Calcium-Activated K Channels: Role of Ligands,Phosphorylation, and G-ProteinsL. TORO and E. STEFANI. With 4 Figures 561

A. Introduction 561B. Mechanisms of Metabolic Regulation of Maxi-KCa Channels 564

I. Ligand Modulation 5641. Arachidonic Acid 5642. Angiotensin II and Thromboxane A2 5653. Guanine Nucleotides 5654. Intracellular pH 566

II. Phosphorylation/Dephosphorylation Cycles 5681. Pituitary Maxi-KCa Channels 5702. Brain Maxi-KCa Channels 5703. Colonic Maxi-Kca Channels 5714. Myometrial Maxi-KCa Channels 571

III. G-Protein Gating 5721. Muscarinic Regulation 5732. Adrenergic Stimulation 574

C. Conclusions 575References 576

CHAPTER 79

Regulation of the Endosomal Proton Translocating ATPase (H+-ATPase)and Endosomal Acidification by G-ProteinsR.W. GURICH and T.D. DUBOSE, JR. With 6 Figures 581

A. Introduction 581B. Endocytosis 581

I. General 581II. The Kidney 582

C. Endosomal Acidification 584I. Potential Role for G-Proteins in Endosomal Acidification . . . . 586

II. Effects of G-Proteins on Endosomal Acidification 588D. Conclusions 592References '. 593

Contents XXXIII

CHAPTER 80

cAMP-Independent Regulation of Adipocyte Glucose TransportActivity and Other Metabolic Processes by a Complex of Receptorsand Their Associated G-ProteinsC. LONDOS and LA. SIMPSON. With 4 Figures 597

A. Introduction 597B. Lack of a Relationship Between cAMP and Glucose Transporter

Activity 598C. G-Proteins in Glucose Transporter Regulation 600D. How Do G-Proteins Mediate Glucose Transporter Activity? 602E. Other RSGS- and RiGrMediated Processes in Adipocytes 605F. Conclusions and Speculations 606References 607

Subject Index 611