title: Expression, desensitization, and internalization of the ACTH receptor (MC2R).
abstract: Research into the functions and mechanisms of action of the melanocortin 2 receptor (MC2R) has been severely hampered by difficulties in expressing this gene in heterologous cells. This probably arises because of the need for a cofactor for cell surface expression. Using either the Y1 cell line that expresses endogenous MC2R or the Y6 cell line that expresses this putative expression factor, we have explored the mechanisms of desensitization and internalization after agonist stimulation. Protein kinase A dependence of desensitization has been demonstrated, although internalization is apparently independent of this kinase and dependent on a G protein receptor kinase. Possible underlying reasons for this paradox are discussed.
authors.affiliation: Department of Endocrinology, Queen Mary University of London, London EC1A 7BE, United Kingdom. a.j.clark@qmul.ac.uk
authors.forename: Adrian J L
authors.initials: AJ
authors.lastname: Clark
authors.forename: Asma H
authors.initials: AH
authors.lastname: Baig
authors.forename: Luke
authors.initials: L
authors.lastname: Noon
authors.forename: Francesca M
authors.initials: FM
authors.lastname: Swords
authors.forename: Laszlo
authors.initials: L
authors.lastname: Hunyady
authors.forename: Peter J
authors.initials: PJ
authors.lastname: King
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism; D004705:Endocytosis / Q000502:physiology; D006801:Humans; D044103:Receptor, Melanocortin, Type 2; D018043:Receptors, Corticotropin / Q000235:genetics / Q000378:metabolism*
chemical_list: D044103:Receptor, Melanocortin, Type 2; D018043:Receptors, Corticotropin; D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases