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This Article Accepted manuscript (PDF) All Versions of this Article: JOE-08-0276v1 201/2/185    most recent Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Munoz, M. Articles by Dominici, F. Search for Related Content PubMed PubMed Citation Articles by Munoz, M. Articles by Dominici, F.

M Munoz, IQUIFIB, Facultad de Farmacia y Bioquimica, UBA, Buenos Aires, Argentina
J Giani, IQUIFIB, Facultad de Farmacia y Bioquimica, UBA, Buenos Aires, Argentina
M Mayer, Catedra de Farmacologia, Facultad de Farmacia y Bioquimica, Buenos Aires, Argentina
J Toblli, Laboratory of Experimental Medicine, Hospital Aleman, Buenos Aires, Argentina
D Turyn, IQUIFIB, Facultad de Farmacia y Bioquimica, UBA, Buenos Aires, Argentina
F Dominici, IQUIFIB, Facultad de Farmacia y Bioquimica, UBA, Buenos Aires, Argentina

Correspondence: Fernando Dominici, Email: dominici{at}qb.ffyb.uba.ar

Abstract

The IkB kinase-beta (IKK-beta)/Nuclear factor (NF)-kB signaling pathway has been suggested to link inflammation with obesity and insulin resistance. In addition, angiotensin (Ang) II is able to induce insulin resistance and an inflammatory state throught Ang II receptor type 1 (AT1R). Accordingly, we examined whether inhibition of AT1R with irbesartan (IRB) can protect against the development of insulin resistance in obese Zucker rats (OZR). Irbesartan-treatment improved the insulin-stimulated insulin receptor (IR) phosphorylation at tyrosines (Tyr) residues 1158, 1162, 1163 (involved in activation of the IR kinase) and at Tyr 972 (involved in substrate recognition). AT1R blockade also originated a dramatic increase in the phosphorylation of Akt and glycogen synthase kinase-3beta (GSK-3beta). This was accompanied by a decrease in phosphorylation of IR on serine (Ser) 994, a residue that seems to be implicated in the regulation of IR kinase in OZR. In this study, we demonstrate that Ser 994 of IR is a direct substrate for TANK-binding kinase 1 (TBK1), a new member of the IKK-related kinase family. TBK1 was found to co-immunoprecipitate with the IR, in liver of OZR supporting an in vivo association between the IR and TBK1. Interestingly, a marked increase in the association between TBK1 and the IR was found in liver of OZR as well as in other models of insulin resistance/diabetes. Taken together, these findings suggest that TBK1 could be involved in the insulin resistance mechanism related with IR Ser 994 phosphorylation in a genetic model of diabetes.