| Interacting proteins: Q07666 and P06239 |
Pubmed |
SVM Score :0.0 |
| Interaction between Sam 68 and Src family tyrosine kinases , Fyn and Lck , in T cell receptor signaling . ^^^ Sam 68 was associated with the Src homology 2 and 3 domains of Fyn and also those of another Src family kinase , Lck . ^^^ These data suggest that Sam 68 participates in the signal transduction pathway downstream of TCR coupled Src family kinases Fyn and Lck in lymphocytes , that is not only in the mitotic pathway downstream of c Src in fibroblasts . . ^^^ |
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| Interacting proteins: Q07666 and P06239 |
Pubmed |
SVM Score :0.0 |
| It is dependent on CD 4 expression and , in part , on the association of CD 4 with p56lck , as shown by the strongly decreased association of Sam 68 with p120GAP in the CD 4 mutants , HUT 78 CD4 , and by the reduced association of Sam 68 with both p120GAP and p56lck in the HUT 78 T cell line expressing a CD 4 mutant unable to interact with p56lck , HUT 78 C420 / 22 . ^^^ We propose that recruitment of Sam 68 , via CD4 / p56lck , to the inner face of the plasma membrane may permit , via its docking properties , the correct association of key signaling molecules including PLC gamma 1 and p120GAP . ^^^ |
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| Interacting proteins: Q07666 and P06239 |
Pubmed |
SVM Score :0.0 |
| By overexpressing the two proteins , we show that the constitutive phosphorylation of Sam 68 in vivo directly correlates with cellular Fyn levels , but not with Lck expression , despite the capacity of the PTK to strongly phosphorylate the molecule in vitro . ^^^ |
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| Interacting proteins: Q07666 and P06239 |
Pubmed |
SVM Score :0.0 |
| Immunoprecipitation and in vitro kinase assays reveal rapid GC induced down modulation of Lck and Fyn kinases using SAM 68 ( Src [ pp60c src ] associated in mitosis 68 kDa ) as a substrate . ^^^ |
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| Interacting proteins: Q07666 and P06239 |
Pubmed |
SVM Score :0.0 |
| On the other hand , we confirmed previously mapped Lck SH 3 binding sites in ADAM 15 , HS 1 , SLP 76 , and NS5A , and identified putative Lck SH 3 binding sites of Sam 68 , FasL , c Cbl , and Cbl b . ^^^ Possible explanations for the observed variations between artificial and native ligands which are not due to significant K ( D ) value differences as shown by calculating Lck SH 3 affinities of artificial peptide PD 1 Y ( 3 ) R as well as for peptides comprising putative Lck SH 3 binding sites of NS5A , Sos , and Sam 68 are discussed . ^^^ |
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| Interacting proteins: Q07666 and P06239 |
Pubmed |
SVM Score :0.8343683 |
| Furthermore in Jurkat T cell extracts , a recombinant intron B plus SH 3 p56lck domain fails to interact with some TCR induced tyrosine phosphorylated polypeptides and known p56lck partners such as Sam 68 and c Cbl . 0.8343683^^^ |
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| Interacting proteins: Q07666 and P06239 |
Pubmed |
SVM Score :0.0 |
| A direct interaction between Sam 68 and the two src kinases involved in T cell activation , p 59 ( fyn ) and p 56 ( lck ) , as well as a partnership of Sam 68 with various key downstream signaling molecules , like phospholipase Cgamma 1 and Grb 2 , has been shown . ^^^ In this study we analyze the contribution of p 56 ( lck ) , as well as the role of ZAP 70 , the second class of protein tyrosine kinase involved in T cell activation , in Sam 68 tyrosine phosphorylation in the human Jurkat T cell line . ^^^ Using the src inhibitor PP 1 [ 4 amino 5 ( 4 methylphenyl ) 7 ( t butyl ) pyrazolo [ 3 , 4 d ] pyrymidine ] and cell variants with defective expression of p 56 ( lck ) or expressing a dominant negative form of ZAP 70 , we demonstrate that , while both p 56 ( lck ) and ZAP 70 are dispensable for the low constitutive phosphorylation of Sam 68 observed in Jurkat cells , a cooperation between the two kinases is required to increase its rapid phosphorylation observed in vivo after CD 3 stimulation . ^^^ We also show that recombinant forms of both p 56 ( lck ) and ZAP 70 phosphorylate Sam 68 in vitro . ^^^ However , using CD 2 stimulated cells , we observe that p 56 ( lck ) activation by itself does not induce Sam 68 tyrosine phosphorylation . ^^^ |
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| Interacting proteins: Q07666 and P06239 |
Pubmed |
SVM Score :0.0 |
| The distinct capacity of Fyn and Lck to phosphorylate Sam 68 in T cells is essentially governed by SH3 / SH2 catalytic domain linker interactions . ^^^ Sam 68 phosphorylation correlates with Fyn but not Lck expression in T cells . ^^^ We show that this specificity is not based on a spatial segregation of the two kinases , since a chimeric Lck molecule containing the membrane anchoring domain of Fyn does not phosphorylate Sam 68 . ^^^ Moreover , a Sam 68 molecule targeted to the plasma membrane by the farnesylation signal of c Ha Ras remains poorly phosphorylated by Lck . ^^^ In T cells , Fyn appears to be the active Src kinase in rafts , but Sam 68 is not expressed in rafts , and its distinct phosphorylation by Fyn and Lck is not affected by raft dispersion . ^^^ |
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