Exendin-4 regulates pancreatic ABCA1 transcription via CaMKK/CaMKIV pathway.

ABSTRACT: ATP-binding cassette transporter A1 (ABCA1) in pancreatic beta cells influences insulin secretion and glucose homeostasis. This study investigates whether the long-acting agonist of the glucagon-like peptide 1, namely exendin-4, which mediates stimulatory effects on ABCA1 gene expression, could interfere with the Ca(2+)/calmodulin (CaM)-dependent protein kinase (CaMK) cascade. ABCA1 promoter activity was examined by reporter gene assay in rat insulin-secreting INS-1 cells incubated with exendin-4. CaMKIV activity was assessed by detection of activation-loop phosphorylation (Thr(196)) of CaMKIV. We investigated the influence of the constitutively active form (CaMKIVc) or CaMKIV knockdown on ABCA1 expression. Increased abundance of ABCA1 protein was noted in response to rising concentrations

SUBMITTER: Li J 

PROVIDER: S-EPMC3822745 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature