Nicolas C Nicolaides1,2, Tomoshige Kino3, Michael L Roberts1, Eleni Katsantoni4, Amalia Sertedaki2, Paraskevi Moutsatsou5, Anna-Maria G Psarra6, George P Chrousos1,2,7, Evangelia Charmandari1,2. 1. Division of Endocrinology and Metabolism, Center of Clinical, Experimental Surgery and Translational Research, Biomedical Research Foundation of the Academy of Athens, Athens, Greece. 2. Division of Endocrinology, Metabolism and Diabetes, First Department of Pediatrics, National and Kapodistrian University of Athens Medical School, "Aghia Sophia" Children's Hospital, Athens, Greece. 3. Program in Reproductive and Adult Endocrinology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland. 4. Division of Hematology-Oncology, Basic Research Center, Biomedical Research Foundation of the Academy of Athens, Athens, Greece. 5. Department of Clinical Biochemistry, University of Athens Medical School, "Attiko" Hospital, Athens, 12462, Greece. 6. Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, 41221, Greece. 7. Saudi Diabetes Study Research Group, King Fahd Center for Medical Research, King Abdulaziz University, Jeddah, Saudi Arabia.
Abstract
BACKGROUND: Many rapid nongenomic glucocorticoid actions are mediated by membrane-bound glucocorticoid receptors (GRs). S-palmitoylation is a lipid post-translational modification that mediates the membrane localization of some steroid receptors. A highly homologous amino acid sequence (663YLCM KTLLL671) is present in the ligand-binding domain of hGRα, suggesting that hGRα might also undergo S-palmitoylation. AIM: To investigate the role of the motif 663YLCMKTLLL671 in membrane localization of the hGRα and in mediating rapid nongenomic glucocorticoid signaling. METHODS AND RESULTS: We showed that the mutant receptors hGRαY663A, hGRαC665A and hGRαLL670/671AA, and the addition of the palmitoylation inhibitor 2-bromopalmitate did not prevent membrane localization of hGRα and co-localization with caveolin-1, and did not influence the biphasic activation of mitogen-activated protein kinase (MAPK) signaling pathway in the early time points. Finally, the hGRα was not shown to undergo S-palmitoylation. CONCLUSIONS: The motif 663YLCMKTLLL671 does not play a role in membrane localization of hGRα and does not mediate the nongenomic glucocorticoid actions.
BACKGROUND: Many rapid nongenomic glucocorticoid actions are mediated by membrane-bound glucocorticoid receptors (GRs). S-palmitoylation is a lipid post-translational modification that mediates the membrane localization of some steroid receptors. A highly homologous amino acid sequence (663YLCM KTLLL671) is present in the ligand-binding domain of hGRα, suggesting that hGRα might also undergo S-palmitoylation. AIM: To investigate the role of the motif 663YLCMKTLLL671 in membrane localization of the hGRα and in mediating rapid nongenomic glucocorticoid signaling. METHODS AND RESULTS: We showed that the mutant receptors hGRαY663A, hGRαC665A and hGRαLL670/671AA, and the addition of the palmitoylation inhibitor 2-bromopalmitate did not prevent membrane localization of hGRα and co-localization with caveolin-1, and did not influence the biphasic activation of mitogen-activated protein kinase (MAPK) signaling pathway in the early time points. Finally, the hGRα was not shown to undergo S-palmitoylation. CONCLUSIONS: The motif 663YLCMKTLLL671 does not play a role in membrane localization of hGRα and does not mediate the nongenomic glucocorticoid actions.
Authors: Mark Löwenberg; Auke P Verhaar; Joyce Bilderbeek; Jan van Marle; Frank Buttgereit; Maikel P Peppelenbosch; Sander J van Deventer; Daniel W Hommes Journal: EMBO Rep Date: 2006-08-04 Impact factor: 8.807
Authors: Ali Pedram; Mahnaz Razandi; Richard C A Sainson; Jin K Kim; Christopher C Hughes; Ellis R Levin Journal: J Biol Chem Date: 2007-05-29 Impact factor: 5.157