Synthesis, trafficking, and localization of muscarinic acetylcholine receptors

Abstract

Muscarinic acetylcholine receptors are members of the G-protein coupled receptor superfamily that are expressed in and regulate the function of neurons, cardiac and smooth muscle, glands, and many other cell types and tissues. The correct trafficking of membrane proteins to the cell surface and their subsequent localization at appropriate sites in polarized cells are required for normal cellular signaling and physiological responses. This review will summarize work on the synthesis and trafficking of muscarinic receptors to the plasma membrane and their localization at the cell surface.

Figure 1

Muscarinic receptor sorting signals. TOP: The approximate location of the targeting signals in both the M₂ and M₃ receptors is depicted by the thick line in the third cytoplasmic loop. BOTTOM: The amino acid sequences of the basolateral sorting signal in the M₃ receptor and the apical sorting signal in the M₂ receptor.