S-21 Novel Functions and Regulatory Mechanisms of G Protein-Coupled Receptors   S21-1. Ligand-Dependent Distinct Coupling with G Proteins   S21-2. Oligomerization of GPCR   S21-3. Molecular Mechanism of Regulation of Receptor Type-Specific Gq Signaling by RGS8   S21-4. Regulatory Mechanism of GPCR Function by Its Associated Proteins   S21-5. Histamine H1 Receptor Gene Expression Mechanism as a Target of Therapeutics for Allergy   S21-6. The Role of Lipid Rafts in Trimeric G Protein-Mediated Signal Transduction