title: Identification of B cell adaptor for PI3-kinase (BCAP) as an Abl interactor 1-regulated substrate of Abl kinases.
abstract: In previous work we showed that Abl interactor 1 (Abi-1), by linking enzyme and substrate, promotes the phosphorylation of Mammalian Enabled (Mena) by c-Abl. To determine whether this mechanism extends to other c-Abl substrates, we used the yeast two-hybrid system to search for proteins that interact with Abi-1. By screening a human leukocyte cDNA library, we identified BCAP (B-cell adaptor for phosphoinositide 3-kinase) as another Abi-1-interacting protein. Binding experiments revealed that the SH3 domain of Abi-1 and the C-terminal polyproline structure of BCAP are involved in interactions between the two. In cultured cells, Abi-1 promoted phosphorylation of BCAP not only by c-Abl but also by v-Abl. The phosphorylation sites of BCAP by c-Abl were mapped to five tyrosine residues in the C-terminal region that are well conserved in mammals. These results show that Abi-1 promotes Abl-mediated BCAP phosphorylation and suggest that Abi-1 in general coordinates kinase-substrate interactions.
authors.affiliation: Laboratory of Molecular Oncology, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Maruoka
authors.forename: Jun
authors.initials: J
authors.lastname: Suzuki
authors.forename: Shigehisa
authors.initials: S
authors.lastname: Kawata
authors.forename: Kayo
authors.initials: K
authors.lastname: Yoshida
authors.forename: Noriko
authors.initials: N
authors.lastname: Hirao
authors.forename: Seiichi
authors.initials: S
authors.lastname: Sato
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Goff
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Takeya
authors.forename: Katsuko
authors.initials: K
authors.lastname: Tani
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Shishido
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D006801:Humans; D016374:Oncogene Proteins v-abl / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D016315:Proto-Oncogene Proteins c-abl / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D016374:Oncogene Proteins v-abl; D019000:Phosphotyrosine; D016315:Proto-Oncogene Proteins c-abl