Insulin and cyclic AMP act at different levels on transcription of the L‐type pyruvate kinase gene

FEBS Letters

Cuif, Marie-Hélène¹  Doiron, Bruno¹  Kahn, Axel¹ 

[1] Institut Cochin de Génétique Moléculaire, U. 129 INSERM, Université René Descartes, 24, rue du Faubourg Saint-Jacques, 75014 Paris, France

关键词: L-type pyruvate kinase;    Glucose;    Transcriptional control;    Insulin;    Cyclic AMP;   

DOI  :  10.1016/S0014-5793(97)01260-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

We previously demonstrated that, in hepatocytes in primary culture, the role of insulin on induction of L-type pyruvate kinase (L-PK) gene expression was mainly to induce glucokinase synthesis, needed for glucose phosphorylation to glucose 6-phosphate. However, we show here that when hepatocytes have been isolated from rats starved for 72 h, glucose and constitutive glucokinase expression was not sufficient to fully stimulate the L-PK promoter, low insulin concentrations being still required. In addition, activation remains sensitive to cAMP inhibition, but cannot be reproduced in the absence of insulin by a competitive cAMP antagonist. We propose that both insulin and cAMP act on expression of the L-PK gene at, at least, two levels: positive and negative regulation of glucokinase gene expression, and more downstream levels.

【 授权许可】

Unknown