KENBIKYO Vol.51▶No.1 2016
■Feature Articles: Novel Insights on Transport Systems within and between Cells

Molecular Mechanisms of Melanin-Concentrating Hormone Receptor 1 Internalization

Akie Hamamoto, Seika Mitsuyama, Yuki Kobayashi and Yumiko Saito

Abstract: G-protein-coupled receptors (GPCRs) exist as a superfamily of integral membrane protein receptors that contain seven transmembrane α-helical regions. GPCRs respond to a wide range of ligands and interact with heterotrimeric G-proteins, which further transduce these signals intracellular to appropriate downstream effectors, thereby play an important role in various signaling pathways. Because GPCRs mediate key physiological processes in the body, they are one of the most valuable families of drug targets. Following prolonged ligand stimulation, many GPCRs are transferred from the plasma membrane to intracellular compartments, a process that is termed internalization of receptors. This review will summarize the general mechanism of GPCR internalization. Then, we will focus on the latest data obtained on molecular mechanisms involved in melanin-concentrating hormone receptor 1, which is one of the potential targets of obesity research.

Key words: G-protein coupled receptor (GPCR), internalization, phosphorylation, Melanin-concentrating hormone (MCH), food intake