Xylulose 5-phosphate mediates glucose-induced lipogenesis by xylulose 5-phosphate-activated protein phosphatase in rat liver.

ABSTRACT: Carbohydrate-responsive element binding protein (ChREBP) is a transcription factor that activates lipogenic genes in liver in response to excess carbohydrate in the diet. ChREBP is regulated in a reciprocal manner by glucose and cAMP. cAMP-dependent protein kinase (protein kinase A) phosphorylates two physiologically important sites in ChREBP, Ser-196, which is located near nuclear localization signal sequence (NLS), and Thr-666, within the basic helix-loop-helix (bHLH) site, resulting in inactivation of nuclear translocation of ChREBP and of the DNA-binding activity, respectively. We demonstrate here that crude cytosolic extracts from livers of rats fed a high carbohydrate diet contained protein phosphatase (PPase) activity that dephosphorylated a peptide containing Ser-196, whereas a PPa

SUBMITTER: Kabashima T 

PROVIDER: S-EPMC154306 | biostudies-literature | 2003 Apr

REPOSITORIES: biostudies-literature