The phosphatidylinositol polyphosphate 5-phosphatase SHIP1 associates with the Dok1 phosphoprotein in Bcr-Abl transformed cells Journal Article
| Authors: | Dunant, N. M.; Wisniewski, D.; Strife, A.; Clarkson, B.; Resh, M. D. |
| Article Title: | The phosphatidylinositol polyphosphate 5-phosphatase SHIP1 associates with the Dok1 phosphoprotein in Bcr-Abl transformed cells |
| Abstract: | The initial phase of chronic myelogenous leukemia (CML) is triggered by constitutive protein tyrosine kinase activity of the chimeric kinase p210(bcr-abl) (Bcr-Abl). A major substrate of Bcr-Abl was recently identified as the RasGAP-associated 62 kDa docking protein Dok1. Here, we report complex formation between endogenous Dok1 and the SH2 domain-containing phosphatidylinositol polyphosphate 5-phosphatase SHIP1 in hematopoietic cells expressing Bcr-Abl. Expression of Bcr-Abl induced tyrosine phosphorylation of both Dok1 and SHIP1 and the formation of a Dok1/SHIP1 complex. Tyr(P) SHIP1 was also bound to Shc in Bcr-Abl expressing cells. A small amount of Shc/SHIP1/Dok1 trimolecular complex was detected and this was due to binding of Dok1 to SHIP1 that was bound to Shc. In contrast, association of Dok1 with SHIP1 or RasGAP was mutually exclusive. Both the SH2 domain of SHIP1 and the PTB domain of Dok1 were required for complex formation between the two proteins. Neither the specific activity of SHIP1 as an inositol phosphate 5-phosphatase nor the subcellular localization of SHIP1 appeared to be altered by tyrosine phosphorylation. However, the Dok1/SHIP1 complex was only detected in the cytosolic fraction of Bcr-Abl transformed hematopoietic cells. We propose that interaction between Dok1 and SHIP1 modulates the ability of these two proteins to interact with other cytosolic binding partners. Copyright (C) 2000 Elsevier Science Inc. |
| Keywords: | signal transduction; controlled study; protein phosphorylation; human cell; dna-binding proteins; pathogenesis; polymerase chain reaction; protein localization; animals; protein protein interaction; protein binding; enzyme activity; transfection; chronic myeloid leukemia; cos cells; rna-binding proteins; phosphotransferases (alcohol group acceptor); oncogene proteins, fusion; hematopoietic cell; immunoblotting; cell line, transformed; phosphoproteins; cellular distribution; plasmids; ras proteins; phosphoric monoester hydrolases; phosphoprotein; fusion proteins, bcr-abl; gtp phosphohydrolases; bcr-abl; megakaryocytes; phosphatidylinositol; leukemia, myeloid, chronic; dok; ship; ptb; sh2; humans; human; priority journal; article; polyphosphoinositide |
| Journal Title: | Cellular Signalling |
| Volume: | 12 |
| Issue: | 5 |
| ISSN: | 0898-6568 |
| Publisher: | Elsevier Inc. |
| Date Published: | 2000-05-01 |
| Start Page: | 317 |
| End Page: | 326 |
| Language: | English |
| DOI: | 10.1016/s0898-6568(00)00073-5 |
| PUBMED: | 10822173 |
| PROVIDER: | scopus |
| DOI/URL: | |
| Notes: | Export Date: 18 November 2015 -- Source: Scopus |
