| First Author | Trentin GA | Year | 2001 |
| Journal | J Biol Chem | Volume | 276 |
| Issue | 16 | Pages | 13087-95 |
| PubMed ID | 11116152 | Mgi Jnum | J:68871 |
| Mgi Id | MGI:1933654 | Doi | 10.1074/jbc.M009267200 |
| Citation | Trentin GA, et al. (2001) A mouse homologue of the Drosophila tumor suppressor l(2)tid gene defines a novel Ras GTPase-activating protein (RasGAP)-binding protein. J Biol Chem 276(16):13087-95 |
| abstractText | p120 GTPase-activating protein (GAP) down-regulates Ras by stimulating GTP hydrolysis of active Ras. In addition to its association with Ras, GAP has been shown to bind to several tyrosine-phosphorylated proteins in cells stimulated by growth factors or expressing transforming tyrosine kinase variants. Here we report the cloning and characterization of a novel GAP-binding protein, mTid-1, a DnaJ chaperone protein that represents the murine homolog of the Drosophila tumor suppressor l(2)tid gene. Three alternatively spliced variants of mTid-1 were isolated, two of which correspond to the recently identified hTid-1(L) and hTid-1(S) forms of the human TID1 gene that exhibit opposing effects on apoptosis. We demonstrate that both cytoplasmic precursor and mitochondrial mature forms of mTid-1 associate with GAP in vivo. Interestingly, although mTid-1 is found tyrosine-phosphorylated in v-src-transformed fibroblast cells, GAP selectively binds to the unphosphorylated form of mTid-1. In immunofluorescence experiments, GAP and Tid-1 were shown to colocalize at perinuclear mitochondrial membranes in response to epidermal growth factor stimulation. These findings raise the possibility that Tid chaperone proteins may play a role in governing the conformation, activity, and/or subcellular distribution of GAP, thereby influencing its biochemical and biological activity within cells. |
