Evidence that the AMP‐activated protein kinase stimulates rat liver carnitine palmitoyltransferase I by phosphorylating cytoskeletal components

FEBS Letters

Guzmán, Manuel¹  Carling, David²  Velasco, Guillermo¹  Gómez del Pulgar, Teresa¹ 

[1] Department of Biochemistry and Molecular Biology I, School of Biology, Complutense University, 28040 Madrid, Spain;MRC Cellular Stress Group, MRC Clinical Sciences Centre, Imperial College, School of Medicine, Hammersmith Hospital, DuCane Road, London W12 0NN, UK

关键词: AMP-activated protein kinase;    Carnitine palmitoyltransferase I;    Cytoskeleton;    Hepatocyte;    AICAR;    5-aminoimidazole-4-carboxamide ribonucleoside;    AMPK;    AMP-activated protein kinase;    CPT-I;    carnitine palmitoyltransferase I;   

DOI  :  10.1016/S0014-5793(98)01400-8

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The activity of hepatic carnitine palmitoyltransferase I (CPT-I) may be modulated by interactions with cytoskeletal components [Velasco et al. (1998) J. Biol. Chem. 273, 21497–21504]. We have studied whether the AMP-activated protein kinase (AMPK) is involved in this process. AMPK stimulated CPT-I in permeabilized hepatocytes but not in isolated liver mitochondria. In addition, AMPK abrogated the inhibition of CPT-I of isolated mitochondria induced by a cytoskeletal fraction. These two effects of AMPK were not evident when the kinase was inactivated by pretreatment with protein phosphatase 2C. Cytokeratins 8 and 18 were phosphorylated by AMPK in vitro and by incubation of intact hepatocytes with 5-aminoimidazole-4-carboxamide ribonucleoside, a cell-permeable activator of AMPK. These results provide the first evidence that AMPK stimulates CPT-I by direct phosphorylation of cytoskeletal components.

【 授权许可】

Unknown