title: Constitutively active GPR6 is located in the intracellular compartments.
abstract: We used multiple imaging assays to test the hypothesis that GPR6, a constitutively active Gs-coupled receptor, is present on the cell surface. A pHluorin tag at the N-terminus of rat GPR6 expressed in human embryonic kidney 293 (HEK293) cells was not accessible to protons, chymotrypsin or anti-green fluorescent protein antibody, demonstrating that GPR6 is primarily located in intracellular compartments. Similar intracellular localization of pHluorin-tagged GPR6 was found in striatal neurons, where endogenous GPR6 is expressed. Confirmation of Gs-mediated constitutive activity in HEK293 cells and striatal neurons led us to conclude that GPR6 can signal from intracellular compartments.
authors.affiliation: Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta, GA 30912, USA.
authors.forename: Shalini
authors.initials: S
authors.lastname: Padmanabhan
authors.forename: Amanda G
authors.initials: AG
authors.lastname: Myers
authors.forename: Balakrishna M
authors.initials: BM
authors.lastname: Prasad
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane; D003342:Corpus Striatum / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000235:genetics / Q000378:metabolism*
chemical_list: C427404:Gpr6 protein, rat; D043562:Receptors, G-Protein-Coupled