Shb links SLP-76 and Vav with the CD3 complex in Jurkat T cells.
This study addresses the interactions between the adaptor protein Shb and components involved in T cell signalling, including SLP-76, Gads, Vav and ZAP70. We show that both SLP-76 and ZAP70 co-immunoprecipitate with Shb in Jurkat T cells and that Shb and Vav co-immunoprecipitate when cotransfected in COS cells. We also demonstrate, utilizing fusion protein constructs, that SLP-76, Gads and Vav associate independently of each other to different domains or regions, of Shb. Overexpression of an SH2 domain-defective Shb causes diminished phosphorylation of SLP-76 and Vav and consequently decreased activation of c-Jun kinase upon T cell receptor (TCR) stimulation. Shb was also found to localize to glycolipid-enriched membrane microdomains (GEMs), also called lipid rafts, after TCR stimulation. Our results indicate that upon TCR stimulation, Shb is targeted to these lipid rafts where Shb aids in recruiting the SLP-76-Gads-Vav complex to the T cell receptor zeta-chain and ZAP70.
Lindholm
Cecilia K
CK
Department of Medical Cell Biology, Box 571, Biomedicum, Uppsala University, 75123 Uppsala, Sweden. Cecilia.Lindholm@medcellbiol.uu.se
Henriksson
Maria L
ML
Hallberg
Bengt
B
Welsh
Michael
M
D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D017252:CD3 Complex / Q000378:metabolism* / Q000494:pharmacology; D019556:COS Cells; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D006801:Humans; D048031:JNK Mitogen-Activated Protein Kinases; D019169:Jurkat Cells / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D017354:Point Mutation; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction; D014443:Tyrosine / Q000378:metabolism; D051746:ZAP-70 Protein-Tyrosine Kinase; D020830:rac1 GTP-Binding Protein / Q000235:genetics / Q000378:metabolism; D018909:src Homology Domains
D048868:Adaptor Proteins, Signal Transducing; D017252:CD3 Complex; D002352:Carrier Proteins; C409587:GRAP2 protein, human; D015513:Oncogene Proteins; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D051567:Proto-Oncogene Proteins c-vav; D011948:Receptors, Antigen, T-Cell; D011993:Recombinant Fusion Proteins; C490081:SHB protein, human; C092947:SLP-76 signal Transducing adaptor proteins; C496618:VAV1 protein, human; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D051746:ZAP-70 Protein-Tyrosine Kinase; C497261:ZAP70 protein, human; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D020830:rac1 GTP-Binding Protein