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Modulation of the DNA binding activity of transcription factors CREP, NFκB and HSF by H 2 O 2 and TNFα. Differences between in vivo and in vitro effects
Author(s) -
Jornot Lan,
Petersen Hilke,
Junod Alain F
Publication year - 1997
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(97)01244-1
Subject(s) - iodoacetic acid , transcription factor , p50 , chemistry , in vivo , nf κb , nfkb1 , microbiology and biotechnology , in vitro , transcription (linguistics) , dna binding protein , dna , tumor necrosis factor alpha , biochemistry , biology , signal transduction , gene , endocrinology , enzyme , linguistics , philosophy
Human endothelial cells exposed to H 2 O 2 showed reduced CREP DNA binding activity, enhanced HSF activation, and no induction of NFκB binding activity. Interestingly, H 2 O 2 was able to induce NFκB subunit p65 translocation in the nucleus. In contrast, cells exposed to TNFα showed enhanced CREP binding activity, activation of NFκB and no induction of HSE‐HSF complex. Addition of H 2 O 2 , diamide and iodoacetic acid to the binding reaction mixture markedly reduced the DNA binding ability of the three transcription factors. Thus free sulfhydryls were important in DNA binding activity of CREP, NFκB and HSF, and the lack of induction of NFκB by H 2 O 2 in intact cells was likely caused by oxidation on a thiol, and not by a deficiency in the activation pathway.