Regulation of the trafficking and function of G protein-coupled receptors by Rab1 GTPase in cardiomyocytes.

G protein-coupled receptors (GPCRs) play a crucial role in regulating cardiac growth and function under normal and diseased conditions. It has been well documented that the precise function of GPCRs is controlled by intracellular trafficking of the receptors. Compared with the extensive studies on the events of the endocytic pathway, molecular mechanism underlying the transport process of GPCRs from the endoplasmic reticulum (ER) through the Golgi to the cell surface and regulation of receptor signaling by these processes in cardiac myocytes remain poorly defined. This chapter describes the methods to characterize the function of Rab1 GTPase, which modulates protein transport from the ER to the Golgi apparatus, in the trafficking and signaling of angiotensin II type 1 receptor (AT1R), alpha1-adrenergic receptor (AR), and beta-AR, and in hypertrophic growth in response to agonist stimulation in neonatal cardiac myocytes.