Vanadate fully stimulates insulin receptor substrate‐1 associated phosphatidyl inositol 3‐kinase activity in adipocytes from young and old rats

FEBS Letters

Martı́nez, Carmen²  Molero, Juan C¹  Carrascosa, José M¹  Andrés, Antonio²  Satrústegui, Jorgina¹ 

[1] Departamento de Biologı́a Molecular, Centro de Biologı́a Molecular (CSIC), Facultad de Ciencias, Universidad Autónoma, Cantoblanco, 28049 Madrid, Spain;Departamento de Bioquı́mica, Facultad de Quı́micas, Universidad de Castilla-La Mancha, 13071 Ciudad Real, Spain

关键词: Rat adipocyte;    Vanadate;    Aging;    Insulin resistance;    Glucose transport;    Phosphatidyl inositol-3-kinase;    IR;    insulin receptor;    IRS-1;    insulin receptor substrate-1;    GLUT-4;    glucose transporter 4;    PI 3-kinase;    phosphatidyl inositol 3-kinase;    KRP;    Krebs-Ringer phosphate;    PM;    plasma membrane;    LDM;    low density microsomes;   

DOI  :  10.1016/S0014-5793(98)00258-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Vanadate stimulates adipocyte 2-deoxyglucose transport and GLUT-4 translocation to the membrane through an insulin receptor-independent but wortmannin-inhibitable pathway. Vanadate stimulates PI 3-kinase in anti-IRS-1 immunoprecipitates and the binding between IRS-1 and the p85α subunit of PI 3-kinase. In insulin-resistant adipocytes from old rats vanadate fully stimulates IRS-1-associated PI 3-kinase, but partially activates glucose uptake. We conclude that: (a) vanadate stimulates 2-deoxyglucose uptake using a pathway that converges with that of insulin at the level of PI 3-kinase; and (b) adipocytes from old rats are defective in the insulin pathway at steps located both upstream and downstream of PI 3-kinase.

【 授权许可】

Unknown