PubMed:9407100 JSONTXT

{"project":"sentences","denotations":[{"id":"T1","span":{"begin":0,"end":140},"obj":"Sentence"},{"id":"T2","span":{"begin":141,"end":298},"obj":"Sentence"},{"id":"T3","span":{"begin":299,"end":400},"obj":"Sentence"},{"id":"T4","span":{"begin":401,"end":586},"obj":"Sentence"},{"id":"T5","span":{"begin":587,"end":804},"obj":"Sentence"},{"id":"T6","span":{"begin":805,"end":992},"obj":"Sentence"},{"id":"T7","span":{"begin":993,"end":1189},"obj":"Sentence"},{"id":"T8","span":{"begin":1190,"end":1285},"obj":"Sentence"},{"id":"T9","span":{"begin":1286,"end":1508},"obj":"Sentence"}],"namespaces":[{"prefix":"_base","uri":"http://pubannotation.org/ontology/tao.owl#"}],"text":"The Cbl phosphotyrosine-binding domain selects a D(N/D)XpY motif and binds to the Tyr292 negative regulatory phosphorylation site of ZAP-70.\nThe Cbl protooncogene product has emerged as a novel negative regulator of receptor and non-receptor tyrosine kinases through currently undefined mechanisms. Therefore, determining how Cbl physically interacts with tyrosine kinases is of substantial interest. We recently identified a phosphotyrosine binding (PTB) domain residing within the N-terminal transforming region of Cbl (Cbl-N), which mediated direct binding to ZAP-70 tyrosine kinase. Here, we have screened a degenerate phosphopeptide library and show that the Cbl-PTB domain selects a D(N/D)XpY motif, reminiscent of but distinct from the NPXpY motif recognized by the PTB domains of Shc and IRS-1/2. A phosphopeptide predicted by this motif and corresponding to the in vivo negative regulatory phosphorylation site of ZAP-70 (Tyr(P)292) specifically inhibited binding of ZAP-70 to Cbl-N. A ZAP-70/Y292F mutant failed to bind to Cbl-N, whereas a D290A mutant resulted in a 64% decrease in binding, confirming the importance of the Tyr(P) and Y-2 residues in Cbl-PTB domain recognition. Finally the ZAP-70/Y292F mutant also failed to associate with Cbl-N or full-length Cbl in vivo. These results identify a potential Cbl-PTB domain-dependent role for Cbl in the negative regulation of ZAP-70 and predict potential Cbl-PTB domain binding sites on other protein tyrosine kinases known to interact with Cbl."}

{"project":"relna","denotations":[{"id":"T1","span":{"begin":133,"end":139},"obj":"Protein"},{"id":"T2","span":{"begin":145,"end":148},"obj":"DNA"},{"id":"T3","span":{"begin":326,"end":329},"obj":"DNA"},{"id":"T4","span":{"begin":517,"end":520},"obj":"DNA"},{"id":"T5","span":{"begin":522,"end":527},"obj":"DNA"},{"id":"T6","span":{"begin":788,"end":791},"obj":"Protein"},{"id":"T7","span":{"begin":796,"end":803},"obj":"DNA"},{"id":"T8","span":{"begin":923,"end":929},"obj":"Protein"},{"id":"T9","span":{"begin":976,"end":982},"obj":"Protein"},{"id":"T10","span":{"begin":986,"end":991},"obj":"DNA"},{"id":"T11","span":{"begin":995,"end":1001},"obj":"Protein"},{"id":"T12","span":{"begin":1033,"end":1038},"obj":"DNA"},{"id":"T13","span":{"begin":1202,"end":1208},"obj":"Protein"},{"id":"T14","span":{"begin":1252,"end":1257},"obj":"DNA"},{"id":"T15","span":{"begin":1273,"end":1276},"obj":"DNA"},{"id":"T16","span":{"begin":1355,"end":1358},"obj":"DNA"},{"id":"T17","span":{"begin":1389,"end":1395},"obj":"Protein"},{"id":"T18","span":{"begin":1504,"end":1507},"obj":"DNA"}],"relations":[{"id":"R0","pred":"linked","subj":"T9","obj":"T10"}],"text":"The Cbl phosphotyrosine-binding domain selects a D(N/D)XpY motif and binds to the Tyr292 negative regulatory phosphorylation site of ZAP-70.\nThe Cbl protooncogene product has emerged as a novel negative regulator of receptor and non-receptor tyrosine kinases through currently undefined mechanisms. Therefore, determining how Cbl physically interacts with tyrosine kinases is of substantial interest. We recently identified a phosphotyrosine binding (PTB) domain residing within the N-terminal transforming region of Cbl (Cbl-N), which mediated direct binding to ZAP-70 tyrosine kinase. Here, we have screened a degenerate phosphopeptide library and show that the Cbl-PTB domain selects a D(N/D)XpY motif, reminiscent of but distinct from the NPXpY motif recognized by the PTB domains of Shc and IRS-1/2. A phosphopeptide predicted by this motif and corresponding to the in vivo negative regulatory phosphorylation site of ZAP-70 (Tyr(P)292) specifically inhibited binding of ZAP-70 to Cbl-N. A ZAP-70/Y292F mutant failed to bind to Cbl-N, whereas a D290A mutant resulted in a 64% decrease in binding, confirming the importance of the Tyr(P) and Y-2 residues in Cbl-PTB domain recognition. Finally the ZAP-70/Y292F mutant also failed to associate with Cbl-N or full-length Cbl in vivo. These results identify a potential Cbl-PTB domain-dependent role for Cbl in the negative regulation of ZAP-70 and predict potential Cbl-PTB domain binding sites on other protein tyrosine kinases known to interact with Cbl."}