Bridging the NFAT and NF-kappaB families: NFAT5 dimerization regulates cytokine gene transcription in response to osmotic stress.
The transcription factor NFAT5/TonEBP is evolutionarily the oldest member of the NFAT/Rel family of transcription factors. We show that NFAT5 is uniquely related to NF-kappaB and is the only member of the Rel/NFAT family to be activated by osmotic stress. Like Rel/NF-kappaB proteins but unlike the calcium-regulated NFAT proteins, NFAT5 is constitutively dimeric, and dimerization is essential for DNA binding and transcriptional activity. Using dominant-negative proteins that inhibit NFAT5 dimerization, we show that NFAT5 regulates expression of the TNFalpha and lymphotoxin-beta genes in osmotically stressed T cells. Chromatin immunoprecipitation experiments confirm that NFAT5 binds to the TNFalpha promoter in vivo. We suggest that NFAT5 participates in specific aspects of host defense by upregulating TNF family genes and other target genes in T cells.
López-Rodríguez
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C
The Center for Blood Research and, Department of Pathology, Harvard Medical School, 200 Longwood Avenue, Boston, MA 02115, USA.
Aramburu
J
J
Jin
L
L
Rakeman
A S
AS
Michino
M
M
Rao
A
A
D000449:Aldehyde Reductase / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D016207:Cytokines / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D019281:Dimerization; D006801:Humans; D019169:Jurkat Cells; D008025:Ligases / Q000378:metabolism; D008969:Molecular Sequence Data; D016328:NF-kappa B / Q000378:metabolism*; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D009997:Osmotic Pressure; D014157:Transcription Factors / Q000737:chemistry* / Q000378:metabolism; D014158:Transcription, Genetic; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D016207:Cytokines; D004268:DNA-Binding Proteins; D016328:NF-kappa B; D050778:NFATC Transcription Factors; D009687:Nuclear Proteins; D014157:Transcription Factors; D014409:Tumor Necrosis Factor-alpha; D000449:Aldehyde Reductase; D008025:Ligases; C028812:guanosine 3',5'-polyphosphate synthetases