BCR/ABL-induced Leukemogenesis Causes Phosphorylation of Hef1 and Its Association with Crkl

BCR/ABL is considered responsible for the development of Philadelphia chromosome-positive leukemia. Experimental animal models, such as transgenic mice, have demonstrated unambiguously that Bcr/Abl is capable of inducing leukemogenesis. The adaptor molecule Crkl is a major in vivo substrate of the deregulated Bcr/Abl tyrosine kinase and functions as a molecular link with other signaling proteins. While associated in vivowith Bcr/Abl through its SH3 domain, Crkl can interact simultaneously via its SH2 domain with other tyrosine-phosphorylated proteins.Here we report the identification of prominently tyrosine-phosphorylated proteins with a molecular mass of approximately 110 kDa, which bind specifically to the Crkl SH2 domain in leukemic tissues of P190BCR/ABL transgenic mice. We demonstrate that these proteins are identical to Hef1/Cas-L, which is related to p130Cas. The proto-oncoprotein p120Cbl and Hef1, but not p130Cas, were detectably phosphorylated on tyrosine in P190Bcr/Abl-expressing leukemic cells and were found in complex with Crkl, showing the existence of protein complexes in P190Bcr/Abl leukemic cells, consisting of P190Bcr/Abl, Crkl, and Hef1 or p120Cbl. This supports a model in which Crkl acts as mediator between Bcr/Abl and downstream effectors. Since Hef1 is involved in the β1-integrin signaling pathway, our study demonstrates that Bcr/Abl could specifically interfere with normal β1-integrin signaling. BCR/ABL is considered responsible for the development of Philadelphia chromosome-positive leukemia. Experimental animal models, such as transgenic mice, have demonstrated unambiguously that Bcr/Abl is capable of inducing leukemogenesis. The adaptor molecule Crkl is a major in vivo substrate of the deregulated Bcr/Abl tyrosine kinase and functions as a molecular link with other signaling proteins. While associated in vivowith Bcr/Abl through its SH3 domain, Crkl can interact simultaneously via its SH2 domain with other tyrosine-phosphorylated proteins. Here we report the identification of prominently tyrosine-phosphorylated proteins with a molecular mass of approximately 110 kDa, which bind specifically to the Crkl SH2 domain in leukemic tissues of P190BCR/ABL transgenic mice. We demonstrate that these proteins are identical to Hef1/Cas-L, which is related to p130Cas. The proto-oncoprotein p120Cbl and Hef1, but not p130Cas, were detectably phosphorylated on tyrosine in P190Bcr/Abl-expressing leukemic cells and were found in complex with Crkl, showing the existence of protein complexes in P190Bcr/Abl leukemic cells, consisting of P190Bcr/Abl, Crkl, and Hef1 or p120Cbl. This supports a model in which Crkl acts as mediator between Bcr/Abl and downstream effectors. Since Hef1 is involved in the β1-integrin signaling pathway, our study demonstrates that Bcr/Abl could specifically interfere with normal β1-integrin signaling. Several experimental mouse models have been developed to investigate the oncogenic action of Bcr/Abl, which is causative of the development of chronic myeloid leukemia (CML) 1The abbreviations used are: CML, chronic myeloid leukemia; ALL, acute lymphoblastic leukemia; GST, glutathione S-transferase; mAb, monoclonal antibody; SH2, Src homology region-2; SH3, Src homology region-3. 1The abbreviations used are: CML, chronic myeloid leukemia; ALL, acute lymphoblastic leukemia; GST, glutathione S-transferase; mAb, monoclonal antibody; SH2, Src homology region-2; SH3, Src homology region-3. and Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL), in vivo. Transgenic P190BCR/ABL mice reproducibly develop lymphoblastic leukemia/lymphoma involving cells of pre-B-cell origin or their progenitors (1Heisterkamp N. Jenster G. ten Hoeve J. Zovich D. Pattengale P.K. Groffen J. Nature. 1990; 344: 251-254Crossref PubMed Scopus (590) Google Scholar, 2Voncken J.W. Griffiths S. Greaves M.F. Pattengale P.K. Heisterkamp N. Groffen J. Cancer Res. 1992; 52: 4534-4539PubMed Google Scholar). Established transgenic mice strains expressing P190Bcr/Abl provide an unlimited source and unique opportunity for studying the signal transduction pathways affected by the Bcr/Abl oncoprotein in vivo.The tyrosine kinase activity located in the Abl segment of Bcr/Abl is dramatically increased (3Konopka J.B. Watanabe S.M. Witte O.N. Cell. 1984; 37: 1035-1042Abstract Full Text PDF PubMed Scopus (674) Google Scholar), and this is critical for its transforming capacity. Although it remains unclear which intracellular signaling pathways are crucial to the in vivo oncogenic activity of Bcr/Abl, numerous signaling proteins have been implicated by studies involving patient-derived cell lines or stably transfected cells transformed by Bcr/Abl. However, only few signaling proteins are tyrosine-phosphorylated by Bcr/Abl or in complex with Bcr/Abl in leukemic cells isolated directly from Ph+ patients, indicating the importance of studying the molecular mechanisms behind Bcr/Abl-induced leukemogenesis in an in vivo context. Signaling proteins shown to be affected by Bcr/Abl include p130Cas (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google Scholar), R. ten Hoeve J. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar), R. N. Li J.-L. Pisick E. Sattler M. R. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar), Li N. J. M. Cell. Full Text PDF PubMed Scopus Google Scholar), N. D. D. R. Cell. Full Text Full Text PDF PubMed Scopus Google and Hoeve J. Heisterkamp N. Groffen J. PubMed Google Scholar, J. Full Text PDF PubMed Google Scholar, PubMed Google Crkl protein a of homology with the adaptor protein Hoeve J. Heisterkamp N. Groffen J. Google Scholar, M. S. S. M. Cell. 1992; PubMed Scopus Google Scholar). Crkl of an SH2 and SH3 in the of other is and tyrosine-phosphorylated but tyrosine is in tissues R. J.W. Heisterkamp N. Groffen J. Google Scholar). We and have demonstrated that Crkl is tyrosine-phosphorylated in and an Bcr/Abl protein chronic and but not in or in of leukemia Bcr/Abl Hoeve J. Heisterkamp N. Groffen J. PubMed Google Scholar, J. Full Text PDF PubMed Google Scholar, PubMed Google Scholar). it is tyrosine-phosphorylated in leukemic of and transgenic mice R. J.W. Heisterkamp N. Groffen J. Google Scholar). This that Crkl is a signaling protein to be of in the development of Ph+ SH3 domain of Crkl specifically with in the proto-oncoprotein Abl and in Bcr/Abl Hoeve J. Heisterkamp N. Groffen J. Cancer Res. Google Scholar, J. J. Full Text Full Text PDF PubMed Scopus Google Scholar), the Crkl SH2 domain in its proteins. We and have p120Cbl as a tyrosine-phosphorylated that specifically with the Crkl SH2 domain in cells expressing the Bcr/Abl Ph+ R. ten Hoeve J. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar, M. R. N. Pisick E. G. Li J.-L. Google Scholar). Crkl is associated through its SH2 domain with phosphorylated proteins R. N. Li J.-L. Pisick E. Sattler M. R. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google and substrate p130Cas (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google in cell lines and in Ph+ have been for and which can complexes with phosphorylated p130Cas and through their SH2 M. Cell. PubMed Scopus Google Scholar, J. 1992; Full Text PDF PubMed Google Scholar, Cell. PubMed Scopus Google Scholar, R. N. S. J. PubMed Scopus Google Scholar, S. E. Cell. PubMed Google Scholar, M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). and p130Cas are tyrosine-phosphorylated cell are to and are phosphorylated in and cells M. Cell. PubMed Scopus Google Scholar, J. 1992; Full Text PDF PubMed Google Scholar, Cell. PubMed Scopus Google Scholar, R. N. S. J. PubMed Scopus Google Scholar, S. E. Cell. PubMed Google Scholar, M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar, PubMed Scopus Google Scholar, J. Full Text Full Text PDF PubMed Scopus Google Scholar). Crkl link signaling proteins to Bcr/Abl through its SH2 and SH3 these a for and signaling pathways in the development of Ph+ which with the cell of Ph+ cells G. N. J. M. J. PubMed Scopus Google in R. R. PubMed Scopus Google studying leukemic tissues isolated from transgenic mice expressing the transforming P190Bcr/Abl we the of a of tyrosine-phosphorylated as that associated with the Crkl SH2 domain in We demonstrate that is Hef1/Cas-L, a protein which is phosphorylated on tyrosine β1-integrin in We that Hef1 is in by P190Bcr/Abl in transgenic mice, to is in complex with to an of signal transduction pathways Bcr/Abl-induced that Crkl the tyrosine-phosphorylated proto-oncoprotein in a cell and this to a protein in Ph+ R. ten Hoeve J. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar). the we have demonstrated the of proteins of approximately 110 to the Crkl SH2 domain in from P190BCR/ABL transgenic mice, in to the p120Cbl. The as Hef1/Cas-L, a in that of Hef1 and its tyrosine be for leukemia/lymphoma prominently in Ph+ of not This the cell transformed by the P190Bcr/Abl of proteins is to isolated and cell lines M. S. J. PubMed Scopus Google Scholar). with the cell not the protein Hef1 a signaling mediator of Bcr/Abl in cells of the been that p130Cas is phosphorylated in cells and is associated with Crkl in (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google Scholar). the of the been shown to interact with in cells, is associated with phosphorylated p130Cas M. Cell. PubMed Scopus Google Scholar, J. 1992; Full Text PDF PubMed Google Scholar, R. N. S. J. PubMed Scopus Google Scholar), and the of p130Cas and its with S. E. Cell. PubMed Google Scholar, M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). we p130Cas in the leukemic tissues of P190BCR/ABL transgenic mice. to Hef1, p130Cas not detectably phosphorylated on tyrosine or with Crkl in these been that these proteins have a which on the of the to be phosphorylated only in cells cell or β1-integrin N. Sattler M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). This with the of tyrosine and the that cells or their progenitors are the cell transformed by P190Bcr/Abl in transgenic mice J.W. Griffiths S. Greaves M.F. Pattengale P.K. Heisterkamp N. Groffen J. Cancer Res. 1992; 52: 4534-4539PubMed Google as a protein that tyrosine-phosphorylated β1-integrin J. 1992; PubMed Scopus Google and from a in J. G. Cell. PubMed Scopus Google the p130Cas from M. S. J. PubMed Scopus Google Scholar). Hef1 and p130Cas a and protein The SH3 of Hef1 and in the kinase and the related J. G. Cell. PubMed Scopus Google Scholar, M. S. J. PubMed Scopus Google Scholar, N. Sattler M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar, S. PubMed Scopus Google Scholar). as in p130Cas, in Hef1 to the SH2 of the M. G. R. Cell. Full Text PDF PubMed Scopus Google are located in the domain of to the an increased between tyrosine-phosphorylated Hef1 and Crkl demonstrated cell or β1-integrin in of cells N. Sattler M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). that the between Crkl and Hef1 is by the Crkl SH2 domain and in Hef1, involving the the prominently phosphorylated Hef1, we the of the proto-oncoprotein p120Cbl and its in vivo with Crkl and P190Bcr/Abl in The between Crkl and Hef1 or in leukemic from P190BCR/ABL transgenic mice supports a model in which of the functions of Crkl in Ph+ leukemia is to as a molecular link between Bcr/Abl and downstream signaling proteins. this complexes in Bcr/Abl-induced involving Bcr/Abl, Crkl, and of the Crkl SH2 Hef1, p130Cas, or on the Bcr/Abl protein and the transformed cell is that Crkl proteins can only complex with of the on an Crkl is to Bcr/Abl through its SH3 domain and its tyrosine-phosphorylated to Bcr/Abl, which to a in their of of the deregulated kinase activity of Bcr/Abl. Although this model Crkl SH2 in complexes Bcr/Abl an domain Cell. PubMed Scopus Google Scholar). The of Hef1 and with the Crkl SH2 domain in leukemia a which is by normal signaling such as by or which be to a of the signaling pathways in which Hef1 and model for been for the which through its SH2 domain to phosphorylated Abl kinase and their in and in cells D. Cell. PubMed Scopus Google Scholar, R. Full Text Full Text PDF PubMed Scopus Google Scholar). to the by Crkl, a between Bcr/Abl and Hef1 as for M. R. N. Pisick E. G. Li J.-L. Google and which be the for the between Hef1 and J. G. Cell. PubMed Scopus Google Scholar). The Abl SH2 domain can bind directly in to Hef1 in a which is with the between the SH2 and SH2 domain M. G. R. Cell. Full Text PDF PubMed Scopus Google Scholar). This could the of the identification of protein involved in signaling that is with Bcr/Abl in the that Bcr/Abl the intracellular of the signal transduction we that a protein involved in signaling and cell is tyrosine-phosphorylated and associated with the domain in cells and in a cell R. N. Li J.-L. Pisick E. Sattler M. R. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar). in cells, Crkl is associated through its SH2 domain with phosphorylated p130Cas (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google Scholar), which is implicated in signaling. are with the of Bcr/Abl to the Cell. PubMed Google Scholar), and with the in tyrosine of other proteins in myeloid cell lines R. Pisick E. Li J.-L. Google Scholar), this that to the of Ph+ leukemic cells from are in that have in their to Greaves M.F. Nature. PubMed Scopus Google Scholar). The that P190Bcr/Abl Hef1, a protein involved in a for Bcr/Abl can cell to the Several experimental mouse models have been developed to investigate the oncogenic action of Bcr/Abl, which is causative of the development of chronic myeloid leukemia (CML) 1The abbreviations used are: CML, chronic myeloid leukemia; ALL, acute lymphoblastic leukemia; GST, glutathione S-transferase; mAb, monoclonal antibody; SH2, Src homology region-2; SH3, Src homology region-3. 1The abbreviations used are: CML, chronic myeloid leukemia; ALL, acute lymphoblastic leukemia; GST, glutathione S-transferase; mAb, monoclonal antibody; SH2, Src homology region-2; SH3, Src homology region-3. and Philadelphia-positive (Ph+) acute lymphoblastic leukemia (ALL), in vivo. Transgenic P190BCR/ABL mice reproducibly develop lymphoblastic leukemia/lymphoma involving cells of pre-B-cell origin or their progenitors (1Heisterkamp N. Jenster G. ten Hoeve J. Zovich D. Pattengale P.K. Groffen J. Nature. 1990; 344: 251-254Crossref PubMed Scopus (590) Google Scholar, 2Voncken J.W. Griffiths S. Greaves M.F. Pattengale P.K. Heisterkamp N. Groffen J. Cancer Res. 1992; 52: 4534-4539PubMed Google Scholar). Established transgenic mice strains expressing P190Bcr/Abl provide an unlimited source and unique opportunity for studying the signal transduction pathways affected by the Bcr/Abl oncoprotein in vivo. The tyrosine kinase activity located in the Abl segment of Bcr/Abl is dramatically increased (3Konopka J.B. Watanabe S.M. Witte O.N. Cell. 1984; 37: 1035-1042Abstract Full Text PDF PubMed Scopus (674) Google Scholar), and this is critical for its transforming capacity. Although it remains unclear which intracellular signaling pathways are crucial to the in vivo oncogenic activity of Bcr/Abl, numerous signaling proteins have been implicated by studies involving patient-derived cell lines or stably transfected cells transformed by Bcr/Abl. However, only few signaling proteins are tyrosine-phosphorylated by Bcr/Abl or in complex with Bcr/Abl in leukemic cells isolated directly from Ph+ patients, indicating the importance of studying the molecular mechanisms behind Bcr/Abl-induced leukemogenesis in an in vivo context. Signaling proteins shown to be affected by Bcr/Abl include p130Cas (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google Scholar), R. ten Hoeve J. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar), R. N. Li J.-L. Pisick E. Sattler M. R. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar), Li N. J. M. Cell. Full Text PDF PubMed Scopus Google Scholar), N. D. D. R. Cell. Full Text Full Text PDF PubMed Scopus Google and Hoeve J. Heisterkamp N. Groffen J. PubMed Google Scholar, J. Full Text PDF PubMed Google Scholar, PubMed Google Scholar). The Crkl protein a of homology with the adaptor protein Hoeve J. Heisterkamp N. Groffen J. Google Scholar, M. S. S. M. Cell. 1992; PubMed Scopus Google Scholar). Crkl of an SH2 and SH3 in the of other is and tyrosine-phosphorylated but tyrosine is in tissues R. J.W. Heisterkamp N. Groffen J. Google Scholar). We and have demonstrated that Crkl is tyrosine-phosphorylated in and an Bcr/Abl protein chronic and but not in or in of leukemia Bcr/Abl Hoeve J. Heisterkamp N. Groffen J. PubMed Google Scholar, J. Full Text PDF PubMed Google Scholar, PubMed Google Scholar). it is tyrosine-phosphorylated in leukemic of and transgenic mice R. J.W. Heisterkamp N. Groffen J. Google Scholar). This that Crkl is a signaling protein to be of in the development of Ph+ leukemia. The SH3 domain of Crkl specifically with in the proto-oncoprotein Abl and in Bcr/Abl Hoeve J. Heisterkamp N. Groffen J. Cancer Res. Google Scholar, J. J. Full Text Full Text PDF PubMed Scopus Google Scholar), the Crkl SH2 domain in its proteins. We and have p120Cbl as a tyrosine-phosphorylated that specifically with the Crkl SH2 domain in cells expressing the Bcr/Abl Ph+ R. ten Hoeve J. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar, M. R. N. Pisick E. G. Li J.-L. Google Scholar). Crkl is associated through its SH2 domain with phosphorylated proteins R. N. Li J.-L. Pisick E. Sattler M. R. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google and substrate p130Cas (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google in cell lines and in Ph+ have been for and which can complexes with phosphorylated p130Cas and through their SH2 M. Cell. PubMed Scopus Google Scholar, J. 1992; Full Text PDF PubMed Google Scholar, Cell. PubMed Scopus Google Scholar, R. N. S. J. PubMed Scopus Google Scholar, S. E. Cell. PubMed Google Scholar, M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). and p130Cas are tyrosine-phosphorylated cell are to and are phosphorylated in and cells M. Cell. PubMed Scopus Google Scholar, J. 1992; Full Text PDF PubMed Google Scholar, Cell. PubMed Scopus Google Scholar, R. N. S. J. PubMed Scopus Google Scholar, S. E. Cell. PubMed Google Scholar, M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar, PubMed Scopus Google Scholar, J. Full Text Full Text PDF PubMed Scopus Google Scholar). Crkl link signaling proteins to Bcr/Abl through its SH2 and SH3 these a for and signaling pathways in the development of Ph+ which with the cell of Ph+ cells G. N. J. M. J. PubMed Scopus Google in R. R. PubMed Scopus Google studying leukemic tissues isolated from transgenic mice expressing the transforming P190Bcr/Abl we the of a of tyrosine-phosphorylated as that associated with the Crkl SH2 domain in We demonstrate that is Hef1/Cas-L, a protein which is phosphorylated on tyrosine β1-integrin in We that Hef1 is in by P190Bcr/Abl in transgenic mice, to is in complex with to an of signal transduction pathways Bcr/Abl-induced leukemogenesis. that Crkl the tyrosine-phosphorylated proto-oncoprotein in a cell and this to a protein in Ph+ R. ten Hoeve J. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar). the we have demonstrated the of proteins of approximately 110 to the Crkl SH2 domain in from P190BCR/ABL transgenic mice, in to the p120Cbl. The as Hef1/Cas-L, a in that of Hef1 and its tyrosine be for leukemia/lymphoma prominently in Ph+ of not This the cell transformed by the P190Bcr/Abl of proteins is to isolated and cell lines M. S. J. PubMed Scopus Google Scholar). with the cell not the protein Hef1 a signaling mediator of Bcr/Abl in cells of the been that p130Cas is phosphorylated in cells and is associated with Crkl in (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google Scholar). the of the been shown to interact with in cells, is associated with phosphorylated p130Cas M. Cell. PubMed Scopus Google Scholar, J. 1992; Full Text PDF PubMed Google Scholar, R. N. S. J. PubMed Scopus Google Scholar), and the of p130Cas and its with S. E. Cell. PubMed Google Scholar, M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). we p130Cas in the leukemic tissues of P190BCR/ABL transgenic mice. to Hef1, p130Cas not detectably phosphorylated on tyrosine or with Crkl in these been that these proteins have a which on the of the to be phosphorylated only in cells cell or β1-integrin N. Sattler M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). This with the of tyrosine and the that cells or their progenitors are the cell transformed by P190Bcr/Abl in transgenic mice J.W. Griffiths S. Greaves M.F. Pattengale P.K. Heisterkamp N. Groffen J. Cancer Res. 1992; 52: 4534-4539PubMed Google as a protein that tyrosine-phosphorylated β1-integrin J. 1992; PubMed Scopus Google and from a in J. G. Cell. PubMed Scopus Google the p130Cas from M. S. J. PubMed Scopus Google Scholar). Hef1 and p130Cas a and protein The SH3 of Hef1 and in the kinase and the related J. G. Cell. PubMed Scopus Google Scholar, M. S. J. PubMed Scopus Google Scholar, N. Sattler M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar, S. PubMed Scopus Google Scholar). as in p130Cas, in Hef1 to the SH2 of the M. G. R. Cell. Full Text PDF PubMed Scopus Google are located in the domain of to the an increased between tyrosine-phosphorylated Hef1 and Crkl demonstrated cell or β1-integrin in of cells N. Sattler M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). that the between Crkl and Hef1 is by the Crkl SH2 domain and in Hef1, involving the the prominently phosphorylated Hef1, we the of the proto-oncoprotein p120Cbl and its in vivo with Crkl and P190Bcr/Abl in The between Crkl and Hef1 or in leukemic from P190BCR/ABL transgenic mice supports a model in which of the functions of Crkl in Ph+ leukemia is to as a molecular link between Bcr/Abl and downstream signaling proteins. this complexes in Bcr/Abl-induced involving Bcr/Abl, Crkl, and of the Crkl SH2 Hef1, p130Cas, or on the Bcr/Abl protein and the transformed cell is that Crkl proteins can only complex with of the on an Crkl is to Bcr/Abl through its SH3 domain and its tyrosine-phosphorylated to Bcr/Abl, which to a in their of of the deregulated kinase activity of Bcr/Abl. Although this model Crkl SH2 in complexes Bcr/Abl an domain Cell. PubMed Scopus Google Scholar). The of Hef1 and with the Crkl SH2 domain in leukemia a which is by normal signaling such as by or which be to a of the signaling pathways in which Hef1 and model for been for the which through its SH2 domain to phosphorylated Abl kinase and their in and in cells D. Cell. PubMed Scopus Google Scholar, R. Full Text Full Text PDF PubMed Scopus Google Scholar). to the by Crkl, a between Bcr/Abl and Hef1 as for M. R. N. Pisick E. G. Li J.-L. Google and which be the for the between Hef1 and J. G. Cell. PubMed Scopus Google Scholar). The Abl SH2 domain can bind directly in to Hef1 in a which is with the between the SH2 and SH2 domain M. G. R. Cell. Full Text PDF PubMed Scopus Google Scholar). This could the of the identification of protein involved in signaling that is with Bcr/Abl in the that Bcr/Abl the intracellular of the signal transduction we that a protein involved in signaling and cell is tyrosine-phosphorylated and associated with the domain in cells and in a cell R. N. Li J.-L. Pisick E. Sattler M. R. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar). in cells, Crkl is associated through its SH2 domain with phosphorylated p130Cas (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google Scholar), which is implicated in signaling. are with the of Bcr/Abl to the Cell. PubMed Google Scholar), and with the in tyrosine of other proteins in myeloid cell lines R. Pisick E. Li J.-L. Google Scholar), this that to the of Ph+ leukemic cells from are in that have in their to Greaves M.F. Nature. PubMed Scopus Google Scholar). The that P190Bcr/Abl Hef1, a protein involved in a for Bcr/Abl can cell to the We that Crkl the tyrosine-phosphorylated proto-oncoprotein in a cell and this to a protein in Ph+ R. ten Hoeve J. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar). the we have demonstrated the of proteins of approximately 110 to the Crkl SH2 domain in from P190BCR/ABL transgenic mice, in to the p120Cbl. The as Hef1/Cas-L, a in that of Hef1 and its tyrosine be for leukemia/lymphoma prominently in Ph+ of not This the cell transformed by the P190Bcr/Abl of proteins is to isolated and cell lines M. S. J. PubMed Scopus Google Scholar). with the cell not the protein Hef1 a signaling mediator of Bcr/Abl in cells of the been that p130Cas is phosphorylated in cells and is associated with Crkl in (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google Scholar). the of the been shown to interact with in cells, is associated with phosphorylated p130Cas M. Cell. PubMed Scopus Google Scholar, J. 1992; Full Text PDF PubMed Google Scholar, R. N. S. J. PubMed Scopus Google Scholar), and the of p130Cas and its with S. E. Cell. PubMed Google Scholar, M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). we p130Cas in the leukemic tissues of P190BCR/ABL transgenic mice. to Hef1, p130Cas not detectably phosphorylated on tyrosine or with Crkl in these been that these proteins have a which on the of the to be phosphorylated only in cells cell or β1-integrin N. Sattler M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). This with the of tyrosine and the that cells or their progenitors are the cell transformed by P190Bcr/Abl in transgenic mice J.W. Griffiths S. Greaves M.F. Pattengale P.K. Heisterkamp N. Groffen J. Cancer Res. 1992; 52: 4534-4539PubMed Google Scholar). Hef1 as a protein that tyrosine-phosphorylated β1-integrin J. 1992; PubMed Scopus Google and from a in J. G. Cell. PubMed Scopus Google the p130Cas from M. S. J. PubMed Scopus Google Scholar). Hef1 and p130Cas a and protein The SH3 of Hef1 and in the kinase and the related J. G. Cell. PubMed Scopus Google Scholar, M. S. J. PubMed Scopus Google Scholar, N. Sattler M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar, S. PubMed Scopus Google Scholar). as in p130Cas, in Hef1 to the SH2 of the M. G. R. Cell. Full Text PDF PubMed Scopus Google are located in the domain of to the an increased between tyrosine-phosphorylated Hef1 and Crkl demonstrated cell or β1-integrin in of cells N. Sattler M. R. J. Full Text Full Text PDF PubMed Scopus Google Scholar). that the between Crkl and Hef1 is by the Crkl SH2 domain and in Hef1, involving the the prominently phosphorylated Hef1, we the of the proto-oncoprotein p120Cbl and its in vivo with Crkl and P190Bcr/Abl in The between Crkl and Hef1 or in leukemic from P190BCR/ABL transgenic mice supports a model in which of the functions of Crkl in Ph+ leukemia is to as a molecular link between Bcr/Abl and downstream signaling proteins. this complexes in Bcr/Abl-induced involving Bcr/Abl, Crkl, and of the Crkl SH2 Hef1, p130Cas, or on the Bcr/Abl protein and the transformed cell is that Crkl proteins can only complex with of the on an Crkl is to Bcr/Abl through its SH3 domain and its tyrosine-phosphorylated to Bcr/Abl, which to a in their of of the deregulated kinase activity of Bcr/Abl. Although this model Crkl SH2 in complexes Bcr/Abl an domain Cell. PubMed Scopus Google Scholar). The of Hef1 and with the Crkl SH2 domain in leukemia a which is by normal signaling such as by or which be to a of the signaling pathways in which Hef1 and model for been for the which through its SH2 domain to phosphorylated Abl kinase and their in and in cells D. Cell. PubMed Scopus Google Scholar, R. Full Text Full Text PDF PubMed Scopus Google Scholar). to the by Crkl, a between Bcr/Abl and Hef1 as for M. R. N. Pisick E. G. Li J.-L. Google and which be the for the between Hef1 and J. G. Cell. PubMed Scopus Google Scholar). The Abl SH2 domain can bind directly in to Hef1 in a which is with the between the SH2 and SH2 domain M. G. R. Cell. Full Text PDF PubMed Scopus Google Scholar). This could the of the identification of protein involved in signaling that is with Bcr/Abl in the that Bcr/Abl the intracellular of the signal transduction we that a protein involved in signaling and cell is tyrosine-phosphorylated and associated with the domain in cells and in a cell R. N. Li J.-L. Pisick E. Sattler M. R. Heisterkamp N. Groffen J. J. Full Text Full Text PDF PubMed Scopus Google Scholar). in cells, Crkl is associated through its SH2 domain with phosphorylated p130Cas (4Salgia R. Pisick E. Sattler M. Li J.-L. N. J. Full Text Full Text PDF PubMed Scopus Google Scholar), which is implicated in signaling. are with the of Bcr/Abl to the Cell. PubMed Google Scholar), and with the in tyrosine of other proteins in myeloid cell lines R. Pisick E. Li J.-L. Google Scholar), this that to the of Ph+ leukemic cells from are in that have in their to Greaves M.F. Nature. PubMed Scopus Google Scholar). The that P190Bcr/Abl Hef1, a protein involved in a for Bcr/Abl can cell to the