Control of 4E-BPI expression in mouse Brown adipose tissue by the β3-adrenoceptor

Knockout of the translation inhibitor 4E-BP1 induces an overexpression of uncoupling protein-1 (UCP1) [Nature Medicine 7 (2001) 1128]. A possible inverse control of UCP1 and 4E-BP1 expressions in mouse brown adipose tissue was investigated. Cold-exposure, which increases the expression of UCP1, decreased that of 4E-BP1 mRNA in wild type but not in beta(1)/beta(2)/beta(3)-adrenoceptor knockout mice. Administration of the beta(3)-adrenoceptor agonist CL 316246 decreased 4E-BP1 mRNA by 75% and protein by 41% after 6 and 48 h, respectively. Our data are the first report of a regulation by the beta(3)-adrenoceptor of 4E-BP1 expression. They support a role of the latter in adaptive thermogenesis. (C) 2004 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.