Involvement of p21ras activation in T cell CD69 expression.
The involvement of p21ras in the induction of the early activation antigen CD69 was investigated in T cells. Expression of a v-Ha-ras coding for a constitutively active ras protein in Jurkat cells resulted in CD69 induction on the cell surface. Transfected ras was shown to be constitutively activated and functionally efficient, since it could be immunoprecipitated in the guanosine triphosphate (GTP)-bound form and it induced transactivation of an AP-1 consensus-chloramphenicol acetyltransferase reporter gene. The requirement for ras activation in T cell receptor (TcR) CD3-mediated CD69 induction was also investigated. The expression of a dominant negative c-Ha-ras-N17 mutant markedly reduced the amount of GTP that could be immunoprecipitated from ras proteins after TcR/CD3 triggering in Jurkat cells, and concomitantly decreased TcR/CD3-mediated CD69 induction. These results suggest a central role for ras in TcR/CD3-mediated CD69 expression in T cells.
D'Ambrosio
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Department of Experimental Medicine, University of Rome La Sapienza, Italy.
Cantrell
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DA
Frati
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Santoni
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A
Testi
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R
D015703:Antigens, CD / Q000378:metabolism*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000378:metabolism*; D018801:CD2 Antigens; D017252:CD3 Complex / Q000502:physiology; D006160:Guanosine Triphosphate / Q000378:metabolism; D006801:Humans; D037181:Lectins, C-Type; D008213:Lymphocyte Activation; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D011971:Receptors, Immunologic / Q000378:metabolism; D015398:Signal Transduction; D014162:Transfection; D014407:Tumor Cells, Cultured; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D018801:CD2 Antigens; D017252:CD3 Complex; D006160:Guanosine Triphosphate; D037181:Lectins, C-Type; D016283:Proto-Oncogene Proteins p21(ras); D011948:Receptors, Antigen, T-Cell; D011971:Receptors, Immunologic; D000099192:CD69 Antigens; C501009:HRAS protein, human