Intracellular association of a mutant insulin-like growth factor receptor with endogenous receptors

K Reiss, X Tu, G Romano, F Peruzzi, J Y Wang, R Baserga
2001 Clinical Cancer Research  
The type 1 insulin-like growth factor receptor (IGF-IR) is emerging as a powerful survival factor against a variety of apoptotic agents in many cell types. A mutant IGF-IR designated 486/STOP is known to induce apoptosis and inhibit the growth of human tumor cells in mice. We have investigated the mechanism of action of 486/STOP. To study it, we have developed a new retroviral vector in which we have combined a self-inactivating 5'-long terminal repeat with an inducible heat-shock promoter
more » ... shock protein 70) from Drosophila. Using this technique, we find that the polypeptide encoded by 486/STOP is partially retained within the cell and partially secreted. However, the secreted polypeptide is subsequently taken up by the cells. In both cases, a specific intracellular interaction of 486/STOP with the endogenous IGF-IRs can be demonstrated by coimmunoprecipitation.
pmid:11448933 fatcat:itna7zwknbgejcwkx4nuv3ymvq