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Muscle Contraction and Cell Motility: Fundamentals and Developments

Preface I Skeletal Muscle Electron Microscopic Visualization and Recording of ATP-Induced Myosin Head Power Stroke Producing Muscle Contraction Using the Gas Environmental Chamber Historical Background Materials and Methods The Gas Environmental Chamber Carbon Sealing Film lontophoretic Application of ATP Determination of the Critical Electron Dose Not to Impair Physiological Function of the Specimen Position-Marking of Myosin Heads with Site-Directed Antibodies Recording of Specimen Image and Data Analysis Myosin Head Movement Coupled with ATP Hydrolysis in Living Myosin Filaments in the Absence of Actin Filaments Stability in Position of Individual Myosin Heads in the Absence of ATP Amplitude of ATP-Induced Myosin Head Movement in Hydrated Myosin Filaments Reversal in Direction of ATP-Induced Myosin Head Movement across Myosin Filament Bare Zone Reversibility of ATP-Induced Myosin Head Movement Amplitude of ATP-Induced Movement at Various Regions within a Myosin Head Summary of Novel Features of ATP-Induced Myosin Head Movement Revealed by Experiments Using the EC Novel Features of Myosin Head Power Stroke in the Presence of Actin Filaments Preparation of Actin and Myosin Filament Mixture Conditions to Record ATP-Induced Myosin Head Power Stroke in the Filament Mixture Amplitude of ATP-Induced Myosin Head Power Stroke in the Mixture of Actin and Myosin Filaments Reversibility of ATP-Induced Myosin Head Power Stroke Summary of Novel-Features of ATP-Induced Myosin Head Power Stroke Revealed by Experiments Using the EC Acknowledgment References Studies of Muscle Contraction Using X-Ray Diffraction Introduction Basic Concepts in Diffraction Equatorial Reflections Meridional Reflections The Full 2D Diffraction Pattern: Identifying Structural Mechanisms Conclusion Acknowledgements References Muscle Contraction Revised: Combining Contraction Models with Present Scientific Research Evidence Introduction Findings and Facts That Must Be Part of—or Explained by—a Model for Contraction Structure of the Contractile Apparatus General structure Proteins making up the contractile unit The Internal Environment in a Muscle Cell Energy Consumption During Contraction ATP consumption and ATPase rates during contraction Electric charge changes initiated by ATP Active Force Development Stiffness and General Elastic Properties of the Contractile Unit The Dynamic Contractile Unit What Happens during a Contraction?Importance of Considering Ion Movements as the Base for Contraction Conclusions Acknowledgements References Limitations of in vitro Motility Assay Systems in Studying Molecular Mechanism of Muscle Contraction as Revealed by the Effect of Antibodies to Myosin Head Introduction Historical Background Development of in vitro Motility Assay Systems In vitro Force-Movement Assay Systems Properties of Three Antibodies Used to Position-Mark Myosin Heads at Different Regions within a Myosin Head Different Effects of three Antibodies to Myosin Head between in vitro Actin- Myosin Sliding and Muscle Contraction Antibody 1 (Anti-CAD Antibody) Has No Effect on Both in vitro Actin-Myosin Sliding and Muscle Contraction Antibody 2 (Anti-RLR Antibody) Inhibits in vitro Actin-Myosin Sliding, but Has No Appreciable Effect on Muscle Contraction Antibody 3 (Anti-LD Antibody) Shows No Marked Inhibitory Effect on in vitro Actin-Myosin Sliding, but Has Inhibitory Effect on Ca2+-Activated Muscle Contraction Definite Differences in the Mechanism between in vitro Actin-Myosin Sliding and Muscle Contraction as Revealed by the Effect of Antibodies to Myosin Head Evidence That Myosin Heads Do Not Pass through Rigor Configuration during Their Cyclic Attachment-Detachment with Actin Filaments The Finding That Anti-RLR Antibody Inhibits in vitro Actin-Myosin Sliding but Not Muscle Contraction Suggests That Myosin Head Flexibility at the Converter Domain Is Necessary for in vitro Actin-Myosin Sliding but Not for Muscle Contraction The Finding That Anti-LD Antibody Inhibits Conclusion References Characteristics and Mechanism(s) of Force Generation by Increase of Temperature in Active Muscle Introduction Methods and Materials Experimental Techniques and Procedures Muscle Preparations Abbreviations, Nomenclature and Data Analyses Temperature Dependence of Steady Force Isometric Force and Force during Shortening/Lengthening Effects of Pi and ADP (Products of ATP Hydrolysis)Tension Response to Temperature-Jump During Muscle Shortening and Lengthening Effects of Pi and ADP on T-Jump Force Generation A Minimal Crossbridge Cycle (and Modelling)Some General Observations Unresolved Issues Value of Temperature-Studies Acknowledgements References Mechanism of Force Potentiation after Stretch in Intact Mammalian Muscle Introduction Materials and Methods Animals, Fibre Dissection and Measurements Static Tension Measurements Results Static Tension Effects of Sarcomere Length on Active and Passive Tension Effects of Sarcomere Length on Static Stiffness Discussion Equivalence between Residual Force Enhancement and Static Tension Dependence of Static Stiffness on Sarcomere Length BTS Effects Independence of Static Tension from Crossbridges Residual Force Enhancement and Static Tension Mechanism Conclusions Grants References The Static Tension in Skeletal Muscles and Its Regulation by Titin Introduction Characteristics of the Static Tension Mechanisms of Increase in Non-Cross-Bridge Forces Conclusion and Physiological Implications Acknowledgements References Stiffness of Contracting Human Muscle Measured with Supersonic Shear Imaging Introduction Methods and Materials Theoretical Basis of Supersonic Shear Imaging Some Technical Issues Muscle Activation Level and Stiffness Association of Shear Modulus with Joint Torque Association of Shear Modulus with Motor Unit Activity Usefulness as a Measure of Muscle Activation Level Relations between Length, Force, and Stiffness Length-Dependent Changes in Shear Modulus Linear Association of Force and Shear Modulus Difference between Tetanic and Voluntary Contractions Stiffness Measured during Dynamic Contractions Differences in Shear Modulus among Contraction Types Putative Mechanisms General Conclusions and Perspectives Acknowledgments References Effect of DTT on Force and Stiffness during Recovery from Fatigue in Mouse Muscle Fibres Introduction Methods Fibre Dissection and Measurements Force and Stiffness Measurements Results Discussion Grants References II CARDiAC and Smooth Muscle ATP Utilization in Skeletal and Cardiac Muscle: Economy and Efficiency Introduction The Crossbridge Cycle Dependence of ATP Utilization on Activity, Fiber Type and Species ATP Utilization in Cardiac Muscle The Fenn Effect Future Perspectives References Essential Myosin Light Chains Regulate Myosin Function and Muscle Contraction Structure and Interaction Interfaces of Essential Myosin Light Chains Structure of Myosin II Structure of Essential Myosin Light Chains ELC Interaction Interfaces ELC Phosphorylation Functional Roles of ELCs?ELC/MyHC Interactions ELC/lever arm interactions ELC/motor domain couplings ELC/Actin Interaction ELC/RLC Interaction Phosphorylation of ELC Functional Roles of ELC Isoforms Striated muscle ELC isoforms Smooth muscle ELC isoforms Pathophysiology of ELC Acknowledgment References Regulation of Calcium Uptake into the Sarcoplasmic Reticulum in the Heart Introduction SERCA2a Plays a Central Role in Ca2+Uptake Phospholamban: A Critical Regulator of SERCA2a PLN Mutations Related to Human Cardiomyopathy Enhancement of SR Function Is a Novel Therapeutic Target for Heart Failure Strategies to Increase SERCA2a Protein in Heart Failure Strategies to Modulate SERCA2a to Increase Ca2+ Transport Strategies to Decrease PLN Protein in Heart Failure Strategies to Disrupt the Interaction between SERCA2a and PLN Sarcolipin, a Homologue of PLN, Is an Atrium-Specific Inhibitor of SERCA2a Sarcalumenin Is a Newly Identified Conclusion References The Pivotal Role of Cholesterol and Membrane Lipid Rafts in the Ca2+- Sensitization of Vascular Smooth Muscle Contraction Leading to Vasospasm Introduction SPC Is a Causal Factor of Ca2+-Sensitization Leading to Vasospasm The Signaling Pathway of SPC-Induced Ca2+-Sensitization Leading to Vasospasm Role of Cholesterol and Membrane Lipid Rafts in SPC-Induced Ca2+-Sensitization Leading to Vasospasm Summary Acknowledgments References The Catch State of Molluscan Smooth Muscle Background Structures of Catch Muscles Regulation of Catch Catch Theories Challenges of the Traditional Myosin Head Theory Twitchin Bridges Myosin Heads Tied by Twitchin Myorod Interconnections between Thick Filaments?Additional Kinases and Phosphatases Catch during Active Contraction Conclusion Acknowledgements References III Cell Motility Regulation of Dynein Activity in Oscillatory Movement of Sperm Flagella Introduction Basic Features of Flagellar Movement Dynein Force Generation and Microtubule Sliding in the Axoneme Control of Microtubule Sliding and Bend Formation Regulation of Dynein Activities by Mechanical Signal Outlook Acknowledgments References The Biomechanics of Cell Migration Introduction The Cytoskeleton Cytoskeleton and Cell Type Fundamental Mechanism of Cell Migration Based on Actin Polymerization and Actomyosin Contraction The Role of Microtubules in Maintaining Anterior-Posterior Polarity Variety of Cell Migration Mechanisms Traction Forces Traction Forces Exerted by Fibroblasts Traction Forces Exerted by Dictyostelium Cells and Neutrophils Traction Forces Applied by Keratocytes Mechanosensing and Cell Migration Passive Mechanosensing Active Mechanosensing Contact Guidance Conclusion and Future Perspectives Acknowledgement References Role of Dynamic and Cooperative Conformational Changes in Actin Filaments An Exceptionally Conservative and Multifunctional Protein: Actin Structural Polymorphism of Actin Filaments Cooperative Conformational Changes of Actin Filaments Induced by ABPs Interaction with Cofilin Interaction with Myosin Interaction with Drebrin Interactions with End-Binding ABPs Physiological Roles of Cooperative Polymorphism of Actin Filaments Segregation of ABPs along Actin Filaments Amplification of the Inhibitory Effect Intracellular Signaling Wire Actin Filaments as Mechanosensors Why Is Actin So Conservative?Possible Dynamic Roles of Actin Filaments in Muscle Contraction Acknowledgement References

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