Interaction of p85 subunit of PI 3‐kinase with insulin and IGF‐1 receptors analysed by using the two‐hybrid system

FEBS Letters

Bucchini, D.¹  Jami, J.¹  Lamothe, B.¹  Joshi, R.L.¹ 

[1] Institut Cochin de Génétique Moléculaire, INSERM U257, 24 rue du Faubourg Saint Jacques, 75014 Paris, France

关键词: Insulin receptor;    IGF-1 receptor;    Signal transduction;    Phosphatidylinositol 3-kinase;    Two-hybrid system;    IGF-1;    insulin-like growth factor-1;    PI 3-kinase;    phosphatidylinositol 3-kinase;    aa;    amino acid;    C;    Cys;    H;    His;    M;    Met;    N;    Asn;    P;    Pro;    R;    Arg;    T;    Thr;    Y;    Tyr;    X;    any of the 20 aa;   

DOI  :  10.1016/0014-5793(95)01011-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Interaction of the p85 subunit of PI 3-kinase with the insulin receptor (IR) and the IGF-1 receptor (IGF-1R) was investigated using the two-hybrid system by assessing for his3 and lacZ activation in S. cerevisiae. The experiments were performed with the cytoplasmic β domain (wild type or mutated) of IR and IGF-1R and p85 or its subdomains (N + C-SH2, N-SH2, C-SH2, SH3 + N-SH2). The results of his3 activation indicated that p85, N + C-SH2 and C-SH2 interact with both IRβ and IGF-1Rβ, whereas N-SH2 and SH3 + N-SH2 interact only with IRβ. Interaction of p85 and N + C-SH2 with IRβ(ΔC-43) or IGF-1Rβ(ΔC-43) in which the C-terminal 43 amino acids (including the YXXM motif) were deleted, persisted. The internal binding site thus revealed was not altered by further mutating Y⁹⁶⁰/F for IR or Y⁹⁵⁰/F for IGF-1R. Activation of lacZ upon interaction of p85 with IRβ(ΔC-43) was 4-fold less as compared to IRβ. This activation with p85 and IGF-1Rβ was 4-fold less as compared to IRβ and was somewhat increased (2-fold) for IGE-1Rβ(ΔC-43). Thus, the C-terminal domain in IGF-1R appears to exert a negative control on binding of p85 thereby providing a possible regulatory mechanism for direct activation of the PI 3-kinase pathway.

【 授权许可】

Unknown