title: Lateral diffusion of Gαs in the plasma membrane is decreased after chronic but not acute antidepressant treatment: role of lipid raft and non-raft membrane microdomains.
abstract: GPCR signaling is modified both in major depressive disorder and by chronic antidepressant treatment. Endogenous Gαs redistributes from raft- to nonraft-membrane fractions after chronic antidepressant treatment. Modification of G protein anchoring may participate in this process. Regulation of Gαs signaling by antidepressants was studied using fluorescence recovery after photobleaching (FRAP) of GFP-Gαs. Here we find that extended antidepressant treatment both increases the half-time of maximum recovery of GFP-Gαs and decreases the extent of recovery. Furthermore, this effect parallels the movement of Gαs out of lipid rafts as determined by cold detergent membrane extraction with respect to both dose and duration of drug treatment. This effect was observed for several classes of compounds with antidepressant activity, whereas closely related molecules lacking antidepressant activity (eg, R-citalopram) did not produce the effect. These results are consistent with previously observed antidepressant-induced translocation of Gαs, but also suggest an alternate membrane attachment site for this G protein. Furthermore, FRAP analysis provides the possibility of a relatively high-throughput screening tool for compounds with putative antidepressant activity.
authors.affiliation: Graduate Program in Neuroscience, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Czysz
authors.affiliation: Departments of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA.
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Schappi
authors.affiliation: 1] Graduate Program in Neuroscience, University of Illinois at Chicago, College of Medicine, Chicago, IL, USA [2] Departments of Physiology and Biophysics, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA [3] Departments of Psychiatry, College of Medicine, University of Illinois at Chicago, Chicago, IL, USA [4] Jesse Brown Westside VA Medical Center, Chicago, IL, USA.
authors.forename: Mark M
authors.initials: MM
authors.lastname: Rasenick
mesh_terms: D000818:Animals; D000928:Antidepressive Agents / Q000008:administration & dosage* / Q000494:pharmacology*; D002460:Cell Line; D004058:Diffusion / Q000187:drug effects*; D036681:Fluorescence Recovery After Photobleaching; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000378:metabolism*; D021962:Membrane Microdomains / Q000187:drug effects* / Q000378:metabolism*; D051381:Rats
chemical_list: D000928:Antidepressive Agents; D019205:GTP-Binding Protein alpha Subunits, Gs