Chapter 5. G Protein-Coupled Signal Transmission Pathways

Summary

This chapter contains sections titled:

• Transmembrane Receptors: General Structure and Classification

• Structural Principles of Transmembrane Receptors

  • The Extracellular Domain of Transmembrane Receptors

  • The Transmembrane Domain

  • The Intracellular Domain of Membrane Receptors

  • Regulation of Receptor Activity

• G Protein-Coupled Receptors

  • Structure of G Protein-Coupled Receptors

  • Ligand Binding

  • Mechanism of Signal Transmission

  • Switching Off and Desensitization of 7-Helix Transmembrane Receptors

  • Dimerization of GPCRs

• Regulatory GTPases

  • The GTPase Superfamily: General Functions and Mechanism

  • Inhibition of GTPases by GTP Analogs

  • The G-domain as Common Structural Element of the GTPases

  • The Different GTPase Families

• The Heterotrimeric G Proteins

  • Classification of the Heterotrimeric G Proteins

  • Toxins as Tools in the Characterization of Heterotrimeric G Proteins

  • The Functional Cycle of Heterotrimeric G Proteins

  • Structural and Mechanistic Aspects of the Switch Function of G Proteins

  • Structure and Function of the βγ-Complex

  • Membrane Association of the G Proteins

  • Regulators of G Proteins: Phosducin and RGS Proteins

• Effector Molecules of G Proteins

  • Adenylyl Cyclase and cAMP as Second Messenger

  • Phospholipase C