Mechanosensitive Ion Channels, Part B (eBook)
616 Seiten
Elsevier Science (Verlag)
978-0-08-049440-1 (ISBN)
MS Channels in Tumor Cell Migration, Mechanosensitive Channels in Regulating Smooth Muscle Contraction in the GI, Mechanosensitive Ion Channels in Blood-Pressure-Sensing Baroreceptor Neurons.
Current Topics in Membranes provides a systematic, comprehensive, and rigorous approach to specific topics relevant to the study of cellular membranes. Each volume is a guest edited compendium of membrane biology. This series has been a mainstay for practicing scientists and students interested in this critical field of biology. Articles covered in the volume include ENaC Proteins in Vascular Smooth Muscle Mechanotransduction; Regulation of the Mechano-Gated K2P Channel TREK-1 by Membrane Phospholipids; MechanoTRPs and TRPA1; TRPC; The Cytoskeletal Connection to Ion Channels as a Potential Mechanosensory Mechanism. Lessons From Polycystin-2 (TRPP2); Lipid Stress at Play: Mechanosensitivity of Voltage-Gated Channels; Hair Cell Mechanotransduction: The Dynamic Interplay between Structure and Function; Pharmacology of Hair Cell MS Channels; Hair Cell Mechanotransduction; Models of Hair Cell Mechanotrasduction; Touch; Mechanosensitive Ion Channels in Dystrophic Muscle; Mechanotransduction in Endothelial Cells;MS Channels in Tumor Cell Migration; Mechanosensitive Channels in Regulating Smooth Muscle Contraction in the GI; Mechanosensitive Ion Channels in Blood-Pressure-Sensing Baroreceptor Neurons.
Front Cover 1
Mechanosensitive Ion Channels, Part B 4
Copyright Page 5
Contents 6
Contributors 14
Foreword 18
Previous Volumes in Series 20
Chapter 1: Mechanosensitive Ion Channels of Spiders: Mechanical Coupling, Electrophysiology, and Synaptic Modulation 23
I. Overview 23
II. Introduction 24
III. Types of Spider Mechanoreceptors 25
IV. Mechanical Coupling 25
V. Mechanotransduction in Slit Sensilla 28
A. The Ionic Selectivity of Spider Mechanosensitive Channels 29
B. The Location of VS-3 Mechanosensitive Channels 30
C. Mechanosensitive Channel Conductance, Density, and pH Sensitivity 31
D. Temperature Sensitivity of Mechanosensitive Channels 33
E. Molecular Characterization of Spider Mechanosensitive Channels 33
VI. Dynamic Properties of Mechanotransduction and Action Potential Encoding 35
VII. Calcium Signaling During Transduction by Spider Mechanoreceptors 36
VIII. Synaptic Modulation of Spider Mechanoreceptors 37
IX. Conclusions 39
Acknowledgments 39
References 39
Chapter 2: Ion Channels for Mechanotransduction in the Crayfish Stretch Receptor 43
I. Overview 43
II. Introduction 44
III. Morphology of the SRO 45
IV. Functional Properties 46
A. General Behavior 46
B. Viscoelastic Properties of the Receptor Muscles 48
C. MSCs in the Receptor Neurons 49
D. Macroscopic Receptor Currents in the Stretch Receptor Neurons 53
E. Pharmacology of the Crayfish MSCs 55
F. Voltage-Gated Ion Channels and the Generation of Impulse Response 58
G. Adaptation: A Multifactor Property 63
V. Summary and Discussion of Future Research Directions 65
Acknowledgments 67
References 67
Chapter 3: Mechanosensitive Ion Channels in Caenorhabditis elegans 71
I. Overview 71
II. Introduction 72
III. C. elegans Mechanosensitive Behaviors 73
IV. C. elegans DEG/ENaCs 77
A. MEC-4 and MEC-10 79
B. UNC-8 and DEL-1 84
C. UNC-105 87
V. C. elegans TRP Ion Channels 88
A. OSM-9 and OCR-2 92
B. TRP-4 93
VI. Concluding Remarks 94
References 95
Chapter 4: Properties and Mechanism of the Mechanosensitive Ion Channel Inhibitor GsMTx4, a Therapeutic Peptide Derived from Tarantula Venom 103
I. Overview 103
II. Introduction 104
III. Properties and Specificity of GsMTx4 107
A. Biochemical and Structural 107
B. Biophysical and Mechanistic 110
C. Specificity 115
IV. Cellular Sites for GsMTx4 117
A. TRPC1 Channel 117
B. TRPC6 Channel 119
V. Potential Therapeutic Uses for GsMTx4 119
A. Cardiac Myocytes and Atrial Fibrillation 119
B. Muscular Dystrophy 121
C. Astrocytes and Gliosis 122
D. Neurite Growth Extension 124
VI. Conclusions 125
References 125
Chapter 5: Mechanosensitive Channels in Neurite Outgrowth 133
I. Overview 133
II. Introduction 134
III. Encoding of Guidance Cues in Axon Pathfinding 134
IV. Requirement of TRP Channels in Calcium-Dependent Axon Pathfinding 136
V. Physical Guidance Cues and Role of Mechanosensitive Ion Channels 138
VI. Ion Channels as Molecular Integrators 141
VII. Concluding Remarks 142
Note Added in Proof 143
Acknowledgments 143
References 144
Chapter 6: ENaC Proteins in Vascular Smooth Muscle Mechanotransduction 149
I. Overview 149
II. Introduction 150
III. DEG/ENaC/ASIC Proteins are Members of a Diverse Protein Family Involved in Mechanotransduction 151
A. ENaC Proteins 151
B. Genetic Link to Mechanotransduction 152
C. Mechanotransduction in C. elegans 153
D. ENaC and Mechanotransduction 155
IV. Involvement of ENaC Proteins in Vascular Smooth Muscle Mechanotransduction 159
A. ENaC Proteins in Pressure-Mediated Myogenic Constriction 159
V. Summary and Future Directions 167
References 167
Chapter 7: Regulation of the Mechano-Gated K2P Channel TREK-1 by Membrane Phospholipids 177
I. Overview 177
II. Introduction 178
III. TREK-1 Stimulation by Membrane Phospholipids 180
IV. TREK-1 Inhibition by Membrane Phospholipids 183
Acknowledgments 190
References 190
Chapter 8: MechanoTRPs and TRPA1 193
I. Overview 193
II. MechanoTRP Channels 196
III. Characteristics of TRPA1 Gene and Protein 197
IV. TRPA1 Expression in Mechanosensory Organs 198
A. Somatosensory Neurons 198
B. Inner Ear 199
V. Function of TRPA1 199
A. Nociception 199
B. Auditory and Vestibular 202
C. Channel Similarities Between Heterologously Expressed TRPA1 and Endogenous Mechanotransducers 203
VI. Proposed Biological Roles for TRPA1 207
References 208
Chapter 9: TRPCs as MS Channels 213
I. Overview 213
II. Introduction 214
III. Practical Aspects of Recording MS Channels 215
IV. Distinguishing Direct vs Indirect MS Channels 217
V. Extrinsic Regulation of Stretch Sensitivity 219
VI. Strategies to Identify MS Channel Proteins 219
VII. General Properties of TRPCs 220
A. TRPC Expression 221
B. TRPC Activation and Function 221
C. TRPC-TRPC Interactions 222
D. TRPC Interactions with Scaffolding Proteins 223
E. Single TRPC Channel Conductance 224
F. TRPC Pharmacology 225
VIII. Evidence for TRPC Mechanosensitivity 225
A. TRPC1 225
B. TRPC2 232
C. TRPC3 234
D. TRPC4 234
E. TRPC6 234
IX. Conclusions 237
Note Added in Proof 239
Acknowledgments 240
References 240
Chapter 10: The Cytoskeletal Connection to Ion Channels as a Potential Mechanosensory Mechanism: Lessons from Polycystin-2 (TRPP2) 255
I. Overview 256
II. Introduction 257
A. The Channel-Cytoskeleton Connection 261
B. Actin Filaments and Their Disruption: Effect of Cytochalasins 263
C. The Superfamily of TRP Channels 269
D. TRP Channels and Mechanosensation 271
E. Cytoskeletal Connections in TRP Channels 273
III. Role of Actin Cytoskeletal Dynamics in PC2-Mediated Channel Function 275
A. Role of PC2 in Health and Disease 275
B. Presence of Actin and Associated Proteins and Effect of CD on Channel Activity in hST 277
C. Effect of Gelsolin and Actin on PC2 Channel Activity in hST 279
IV. Identification of Actin-Binding Protein Interactions with Polycystin-2 283
A. Interaction Between PC2 and alpha-Actinin Revealed by Yeast Two-Hybrid System 283
B. In Vitro and In Vivo Binding of PC2 with alpha-Actinins 286
V. Effect of Hydroosmotic Pressure on PC2 Channel Function: Role of the Cytoskeleton in Osmosensory Function 287
A. Effect of Hydrostatic and Osmotic Pressure on PC2 Channel Regulation 287
VI. The Channel-Cytoskeleton Interface: Structural-Functional Correlates 294
A. Mechanosensitivity and the Lipid Bilayer 294
B. Cytoskeletal Interactions with PC2 295
C. In Search of the Molecular Link 296
D. Elastic Properties of Actin Networks 297
E. Sensory Role of the Actin Cytoskeleton in PC2 Channel Function 302
VII. Perspective and Future Directions 303
References 304
Chapter 11: Lipid Stress at Play: Mechanosensitivity of Voltage-Gated Channels 319
I. Overview 320
II. The System Components 320
A. The Channel Proteins 322
B. Bilayer 323
C. Accessory Proteins 323
III. Big Picture Issues 323
A. Bilayer Mechanics and VGCs 323
B. Prokaryotic VGCs as Ancestral Lipid Stress Detectors? 326
C. MS VGCs and MS TRP Channels: Sharing Insights 327
D. No MS "Motif" Required: Just Say HMMM 330
E. An Imperturbable K-Selective Pore Surrounded by MS Voltage Sensors? 334
F. Alcohol and VGCs: Binding Sites or Bilayer Mechanics? 336
IV. Reversible Stretch-Induced Changes in Particular VGCs 341
A. Kv Channels 341
B. Cav and Kv3 Channels Have Similar Stretch Responses 343
C. Cav: L-Type Channels in Native Preparations 345
D. Nav Channels 346
E. HCN Channels 346
V. Irreversible Stretch-Induced Gating Changes in VGCs 347
VI. Technical Issues 349
A. Applying a Stretching Force to Study MS Modulation of VGC Activity 349
B. Gadolinium Strangeness 351
VII. Summary Comments 352
Acknowledgments 352
References 352
Chapter 12: Hair Cell Mechanotransduction: The Dynamic Interplay Between Structure and Function 361
I. Overview 361
II. Auditory System 362
III. Hair Bundle Structure 363
IV. MET Involves Mechanically Gated Channels 363
V. Where Are These Channels? 365
VI. The Gating Spring Theory 366
VII. How Are the Channels Activated? 369
VIII. To be or Not to be Tethered 371
IX. Characterizing Channel Properties? 373
X. MET Channel Pore 374
XI. Adaptation 376
A. Motor Adaptation 379
B. Multiple Components of Adaptation 380
C. Fast Adaptation 381
D. Functional Role of Adaptation 382
XII. The Dynamic Hair Bundle 383
XIII. Summary and Future Directions 387
Acknowledgments 388
References 388
Chapter 13: Insights into the Pore of the Hair Cell Transducer Channel from Experiments with Permeant Blockers 397
I. Overview 398
II. Introduction 398
III. Ionic Selectivity of the Transducer Channel 399
IV. Permeation and Block of Mechanoreceptor Channels by FM1-43 400
A. Evidence for Permeation of FM1-43 Through the Hair Cell Transducer Channel 400
B. Permeation of FM1-43 Through Other Mechanoreceptors 403
C. FM1-43 as a Screen for Functional Transducer Channels and Mechanoreceptors 404
V. Permeation and Block of the Hair Cell Transducer Channel by Aminoglycoside Antibiotics 404
A. Evidence for Permeation of Aminoglycoside Antibiotics Through the Transducer Channel 404
B. Inferences About the Functional Geometry of the Transducer Channel Pore 406
VI. Transducer Channel Block by Amiloride and Its Derivatives 413
A. Amiloride and Amiloride Derivatives as Permeant Transducer Channel Blockers: A Reinterpretation 413
B. Structure-Activity Sequences for Amiloride and Its Derivatives 416
VII. Conclusions 416
Acknowledgments 418
References 418
Chapter 14: Models of Hair Cell Mechanotransduction 421
I. Overview 421
II. Introduction 422
III. Transduction Channel Properties 423
A. Localization and Number of Transduction Channels in Stereocilia 423
B. Pore Properties 424
C. Molecular Identity of the Transduction Channel 425
IV. Gating 430
A. Transduction Channel Kinetics and Thermodynamics 430
B. Biophysical Concept of the Gating Spring 432
C. Molecular Representation of the Gating Spring 434
V. Active Hair Bundle Motility 437
A. Adaptation 437
B. Spontaneous Oscillations 437
VI. Conclusions 440
References 440
Chapter 15: Touch 447
I. Overview 448
II. Introduction 448
III. Structure of Skin and Touch Receptors 449
A. Epidermis 449
B. Dermis 451
C. Mechanosensory Receptors 451
IV. Physiology of Mechanoreceptive Nerve Fibers 454
A. Low-Threshold Mechanoreceptors 454
B. High-Threshold Mechanoreceptors 456
V. Quantitating Mechanical Responses in Animal Models 457
VI. Electrophysiological Approaches to Mechanosensation in Rodents 458
VII. Mechanosensitive Ion Channels in Cultured Sensory Neurons 459
VIII. Gating MS Ion Channels in DRG Neurons 468
IX. Candidate Ion Channels 469
A. DEG/ENaC Ion Channels 470
B. TRP Ion Channels 472
C. Mechanosensitive Potassium Channels 475
X. Voltage-Gated Channels and Mechanosensation 476
A. Sodium Channels 476
B. Calcium Channels 478
XI. Indirect Signaling Between Sensory Neurons and Nonneuronal Cells 478
XII. Conclusions 479
Acknowledgments 479
References 479
Chapter 16: Mechanosensitive Ion Channels in Dystrophic Muscle 489
I. Overview 489
II. Introduction 490
III. MS Channel Expression During Myogenesis 491
IV. Permeabilty Properties of MS Channels in Skeletal Muscle 492
A. Permeability to Monovalent Cations 492
B. Permeability to Divalent Cations 492
V. Gating 493
A. SA Gating 493
B. Voltage-Sensitive Gating 495
C. Modal Gating in mdx Muscle 496
VI. Pharmacology 500
A. Block by Gadolinium Ion 500
B. Aminoglycoside Antibiotics 502
VII. Conclusions 503
References 504
Chapter 17: MscCa Regulation of Tumor Cell Migration and Metastasis 507
I. Overview 507
II. Introduction 508
III. Different Modes of Migration 509
A. Amoeboid Migration 509
B. Mesenchymal Migration 510
C. Collective Cell Migration 511
D. Mechanisms for Switching Migration Modes 511
IV. Ca2+ Dependence Of Cell Migration 512
A. Measuring [Ca2+]i 512
B. Identifying Ca2+ Influx Pathways 513
C. Ca2+ Dependence of Amoeba Locomotion 514
D. Ca2+ Dependence of Vertebrate Cell Amoeboid Migration 516
E. The Role of [Ca2+]i Gradients and Transients in Mesen chymal Cell Migration 517
V. The Role of MscCa in Cell Migration 521
VI. Can Extrinsic Mechanical Forces Acting on MscCa Switch on Cell Migration? 523
Note Added in Proof 524
Acknowledgments 524
References 524
Chapter 18: Stretch-Activated Conductances in Smooth Muscles 533
I. Overview 533
II. Introduction 534
III. Mechanosensitive Conductances that Generate Inward Currents 536
A. Vascular Smooth Muscle 536
B. Bladder Myocytes 542
C. GI Myocytes 543
IV. Mechanosensitive Conductances That Generate Outward Currents 549
A. Vascular Muscles 549
B. Bladder Smooth Muscle 550
C. Uterine Smooth Muscle 551
D. GI Smooth Muscle 552
References 557
Chapter 19: Mechanosensitive Ion Channels in Blood Pressure-Sensing Baroreceptor Neurons 563
I. Overview 563
II. Introduction 564
III. BR Sensory Transduction 566
A. Vascular Compliance and Viscoelastic Coupling 567
B. Mechanoelectrical Transduction 567
IV. Mechanosensitive Channels in BR Neurons 570
A. Epithelial Na+ Channels 570
B. Acid Sensing Ion Channels 574
C. TRP Channels 577
V. Methodological Limitations and Challenges 580
A. Need for Selective Pharmacological Antagonists 580
B. Complexity of Mechanosensitive Ion Channel Complex(es) 581
C. Heterogeneity of Sensory Neurons 582
VI. Summary and Future Directions 582
Acknowledgments 583
References 583
Index 591
Mechanosensitive Ion Channels of Spiders: Mechanical Coupling, Electrophysiology, and Synaptic Modulation
Andrew S. French; Päivi H. Torkkeli Department of Physiology and Biophysics, Dalhousie University, Halifax, Nova Scotia B3H 1X5, Canada
Publisher Summary
Arthropods have provided several important mechanoreceptor models because of the relatively large size and accessibility of their primary sensory neurons. Three types of spider receptors— tactile hairs, trichobothria, and slit sensilla—have given important information about the coupling of external mechanical stimuli to the neuronal membrane, transduction of mechanical force into receptor current, encoding of afferent action potentials, and efferent modulation of peripheral sensory receptors. Slit sensilla, found only in spiders, are particularly important because they allow intracellular recording from sensory neurons during mechanical stimulation. Experiments on slit sensilla have shown that their mechanosensitive ion channels are sodium selective, blocked by amiloride, and open more at low pH. This evidence suggests that the channels are members of the same molecular family as degenerins, acid-sensitive ion channels, and epithelial sodium channels. Slit sensilla have also yielded evidence about the location, density, single-channel conductance, and dynamic properties of the mechanosensitive channels. Spider mechanoreceptors are modulated in the periphery by efferent neurons and possibly by circulating chemicals. Mechanisms of modulation, intracellular signaling, and role of intracellular calcium are areas of active investigation.
I OVERVIEW
Arthropods have provided several important mechanoreceptor models because of the relatively large size and accessibility of their primary sensory neurons. Three types of spider receptors: tactile hairs, trichobothria, and slit sensilla have given important information about the coupling of external mechanical stimuli to the neuronal membrane, transduction of mechanical force into receptor current, encoding of afferent action potentials, and efferent modulation of peripheral sensory receptors. Slit sensilla, found only in spiders, have been particularly important because they allow intracellular recording from sensory neurons during mechanical stimulation. Experiments on slit sensilla have shown that their mechanosensitive ion channels are sodium selective, blocked by amiloride, and open more at low pH. This evidence suggests that the channels are members of the same molecular family as degenerins, acid-sensitive ion channels, and epithelial sodium channels. Slit sensilla have also yielded evidence about the location, density, single-channel conductance, and dynamic properties of the mechanosensitive channels. Spider mechanoreceptors are modulated in the periphery by efferent neurons, and possibly by circulating chemicals. Mechanisms of modulation, intracellular signaling, and the role of intracellular calcium are areas of active investigation.
II INTRODUCTION
Humans inhabit a sensory world dominated by vision, but we also use mechanotransduction to provide the senses of hearing, vestibular sensation, touch, and vibration, as well as chemotransduction for the senses of taste and smell. In contrast to our visual world, a spider's life is dominated by vibration and other mechanical inputs, even in those spider species that have relatively good vision. Waiting for prey to land on a web, hunting along the ground or on a plant, and negotiating a vibratory mating ritual—in all their daily activities the mechanical senses are vitally important. In addition, both humans and spiders detect a variety of internally generated mechanical signals from their musculoskeletal systems and internal organs that allow feedback regulation of movement and many internal physiological processes.
Although mechanotransduction is such an important sense for humans, spiders, and most other animals, its fundamental mechanisms have been difficult to unravel, mainly due to the small size and complex morphology of most mechanoreceptor endings. Arthropods (insects, arachnids, and crustaceans) not only possess large arrays of different mechanoreceptors, but the relatively large sizes of some of their sensory neurons, and the close association of many mechanosensory neurons to the external cuticle have provided several model systems for investigating fundamental mechanisms of mechanotransduction.
The most crucial step in mechanotransduction is a change in cell membrane potential, the receptor potential, produced by the application of a mechanical stimulus to the cell. To study this phenomenon ideally requires a preparation where the electrical event can be directly observed during accurately controlled mechanical stimulation. This is possible in several spider preparations, and the information thus obtained will be the major subject here.
III TYPES OF SPIDER MECHANORECEPTORS
The hairiness of spiders is well known, but what are the functions of the thousands of hairs covering a typical spider? Many provide nonsensory functions. These include adhesion to the substrate via surface tension, combing of silk threads from spinnerets, supporting the air bubbles of water spiders, providing attachment sites for spiderlings clinging to a female, and deterring predators by intense skin irritation (reviewed by Foelix, 1996). However, most of the surface hairs are sensory structures. Two major types of sensory hairs are the trichobothria, or filiform hairs, and the shorter tactile hairs (Fig. 1). Each of these hair structures is innervated by multiple neurons, typically four in Cupiennius salei, although it is not clear that all these neurons are mechanically sensitive. This situation contrasts somewhat with insects, which typically have only one sensory neuron per hair, but the general structures are otherwise similar.
In addition to hairs that extend beyond the cuticle, embedded in spider cuticle are numerous mechanoreceptors of a type that is not found in other arthropods, the slit sensilla (Figs. 1 and 2). These are widely distributed in the exoskeleton, including the legs, pedipalps, and body (Barth and Libera, 1970; Barth, 1985, 2001; Patil et al., 2006). They detect mechanical events in the cuticle, primarily strains imposed by normal movements of the animal and vibrations due to predators, prey, and mates.
Spiders also possess a range of mechanoreceptors deeper within the animal, particularly the joint receptors and muscle receptors, but spiders apparently lack the chordotonal structures that are widespread in insects and crustaceans, serving particularly as vibration and auditory receptors (Seyfarth, 1985; Barth, 2001).
IV MECHANICAL COUPLING
The first functional stage of any mechanoreceptor is mechanical coupling from the initial stimulus to the mechanically sensitive membrane of the sensory neuron. A large contribution to overall function is suggested, although not yet proven, by the wide range of accessory structures found in mechanoreceptors of both vertebrates and invertebrates, which are assumed to serve a mechanical coupling role. Detailed quantitative understanding of this coupling function is limited by the relatively small sizes of most receptors and the unknown mechanical properties of the materials used to construct the structures surrounding the sensory endings. The dynamic properties of coupling structures are particularly difficult to elucidate because it is hard to measure the individual movements of each component as the sensillum is mechanically stimulated.
Barth (2001, 2004) has discussed in depth the...
Erscheint lt. Verlag | 21.9.2011 |
---|---|
Mitarbeit |
Herausgeber (Serie): Dale J. Benos, Sidney A. Simon |
Sprache | englisch |
Themenwelt | Sachbuch/Ratgeber |
Naturwissenschaften ► Biologie ► Biochemie | |
Naturwissenschaften ► Biologie ► Genetik / Molekularbiologie | |
Naturwissenschaften ► Biologie ► Zellbiologie | |
Technik | |
ISBN-10 | 0-08-049440-4 / 0080494404 |
ISBN-13 | 978-0-08-049440-1 / 9780080494401 |
Haben Sie eine Frage zum Produkt? |
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