Glucose and cAMP regulate the L-type pyruvate kinase gene by phosphorylation/dephosphorylation of the carbohydrate response element binding protein.

ABSTRACT: Recently we purified and identified a previously uncharacterized transcription factor from rat liver binding to the carbohydrate responsive element of the L-type pyruvate kinase (L-PK) gene. This factor was named carbohydrate responsive element binding protein (ChREBP). ChREBP, essential for L-PK gene transcription, is activated by high glucose and inhibited by cAMP. Here, we demonstrated that (i) nuclear localization signal and basic helix-loop-helix/leucine-zipper domains of ChREBP were essential for the transcription, and (ii) these domains were the targets of regulation by cAMP and glucose. Among three cAMP-dependent protein kinase phosphorylation sites, Ser(196) and Thr(666) were the target sites. Phosphorylation of the former resulted in inactivation of nuclear import, and that of th

SUBMITTER: Kawaguchi T 

PROVIDER: S-EPMC61106 | biostudies-literature | 2001 Nov

REPOSITORIES: biostudies-literature