HuR binds a cyclic nucleotide-dependent, stabilizing domain in the 3′ untranslated region of Na+/glucose cotransporter (SGLT1) mRNA

Differentiation-dependent expression of the Na+/glucose cotransporter (SGLT1) is accompanied by a large, cAMP-dependent increase in stability of its mRNA. Stabilization is mediated by protein binding to a critical uridine-rich element (URE) in its 3' untranslated region. In the present study, we demonstrate that HuR, an RNA binding protein of the embryonic lethal abnormal vision family, binds the SGLT1 URE. HuR binding was increased after elevation of intracellular cAMP levels and was dependent on protein phosphorylation. This interaction was prevented by a substitution mutation previously shown to block cAMP-dependent reporter message stabilization. These results implicate HuR as a key mediator of cAMPdependent SGLT1 mRNA stabilization. (C) 2001 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.