Requirement of the Src homology 2 domain protein Shb for T cell receptor-dependent activation of the interleukin-2 gene nuclear factor for activation of T cells element in Jurkat T cells.
Stimulation of the T cell antigen receptor (TCR) induces tyrosine phosphorylation of numerous intracellular proteins. We have recently investigated the role of the adaptor protein Shb in the early events of T cell signaling and observed that Shb associates with Grb2, linker for activation of T cells (LAT) and the TCR zeta-chain in Jurkat cells. We now report that Shb also associates with phospholipase C-gamma1 (PLC-gamma1) in these cells. Overexpression of Src homology 2 domain defective Shb caused diminished phosphorylation of LAT and consequently the activation of mitogen-activated protein kinases was decreased upon TCR stimulation. In addition, the Shb mutant also blocked phosphorylation of PLC-gamma1 and the increase in cytoplasmic Ca(2+) following TCR stimulation. Nuclear factor for activation of T cells is a major target for Ras and calcium signaling pathways in T cells following TCR stimulation, and the overexpression of the mutant Shb prevented TCR-dependent activation of the nuclear factor for activation of T cells. Consequently, endogenous interleukin-2 production was decreased under these conditions. The results indicate a role for Shb as a link between the TCR and downstream signaling events involving LAT and PLC-gamma1 and resulting in the activation of transcription of the interleukin-2 gene.
Lindholm
C K
CK
Department of Medical Cell Biology, Box 571, Biomedicum, Uppsala University, S-75123 Uppsala, Sweden.
Gylfe
E
E
Zhang
W
W
Samelson
L E
LE
Welsh
M
M
D048868:Adaptor Proteins, Signal Transducing; D019943:Amino Acid Substitution; D002118:Calcium / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D066246:ErbB Receptors / Q000276:immunology; D051380:GRB2 Adaptor Protein; D005786:Gene Expression Regulation / Q000276:immunology; D006801:Humans; D007376:Interleukin-2 / Q000235:genetics*; D007527:Isoenzymes / Q000378:metabolism; D019169:Jurkat Cells; D008213:Lymphocyte Activation; D008565:Membrane Proteins / Q000276:immunology*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D051966:Phospholipase C gamma; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011506:Proteins / Q000276:immunology; D011518:Proto-Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000276:immunology*; D011994:Recombinant Proteins / Q000378:metabolism; D013601:T-Lymphocytes / Q000276:immunology*; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection; D010738:Type C Phospholipases / Q000378:metabolism; D018909:src Homology Domains
D048868:Adaptor Proteins, Signal Transducing; D004268:DNA-Binding Proteins; D051380:GRB2 Adaptor Protein; C495948:GRB2 protein, human; D007376:Interleukin-2; D007527:Isoenzymes; D008565:Membrane Proteins; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D011506:Proteins; D011518:Proto-Oncogene Proteins; D011948:Receptors, Antigen, T-Cell; D011994:Recombinant Proteins; C490081:SHB protein, human; D014157:Transcription Factors; C054979:antigen T cell receptor, zeta chain; D066246:ErbB Receptors; D011505:Protein-Tyrosine Kinases; D020928:Mitogen-Activated Protein Kinases; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D002118:Calcium