Recombinant NFAT1 (NFATp) is regulated by calcineurin in T cells and mediates transcription of several cytokine genes.
Transcription factors of the NFAT family play a key role in the transcription of cytokine genes and other genes during the immune response. We have identified two new isoforms of the transcription factor NFAT1 (previously termed NFATp) that are the predominant isoforms expressed in murine and human T cells. When expressed in Jurkat T cells, recombinant NFAT1 is regulated, as expected, by the calmodulin-dependent phosphatase calcineurin, and its function is inhibited by the immunosuppressive agent cyclosporin A (CsA). Transactivation by recombinant NFAT1 in Jurkat T cells requires dual stimulation with ionomycin and phorbol 12-myristate 13-acetate; this activity is potentiated by coexpression of constitutively active calcineurin and is inhibited by CsA. Immunocytochemical analysis indicates that recombinant NFAT1 localizes in the cytoplasm of transiently transfected T cells and translocates into the nucleus in a CsA-sensitive manner following ionomycin stimulation. When expressed in COS cells, however, NFAT1 is capable of transactivation, but it is not regulated correctly: its subcellular localization and transcriptional function are not affected by stimulation of the COS cells with ionomycin and phorbol 12-myristate 13-acetate. Recombinant NFAT1 can mediate transcription of the interleukin-2, interleukin-4, tumor necrosis factor alpha, and granulocyte-macrophage colony-stimulating factor promoters in T cells, suggesting that NFAT1 contributes to the CsA-sensitive transcription of these genes during the immune response.
Luo
C
C
Division of Cellular and Molecular Biology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, Massachusetts 02115, USA.
Burgeon
E
E
Carew
J A
JA
McCaffrey
P G
PG
Badalian
T M
TM
Lane
W S
WS
Hogan
P G
PG
Rao
A
A
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D016207:Cytokines / Q000096:biosynthesis*; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D005786:Gene Expression Regulation; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000096:biosynthesis; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D051379:Mice; D008969:Molecular Sequence Data; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D013601:T-Lymphocytes / Q000502:physiology*; D014157:Transcription Factors / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D016207:Cytokines; D017931:DNA Primers; D004268:DNA-Binding Proteins; D007376:Interleukin-2; D050778:NFATC Transcription Factors; C494006:NFATC2 protein, human; C494007:Nfatc2 protein, mouse; D009687:Nuclear Proteins; D011994:Recombinant Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D015847:Interleukin-4; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D015500:Chloramphenicol O-Acetyltransferase