Nakshatri, HarikrishnaBhat-Nakshatri, PoornimaCurrie, R. Alexander2019-04-162019-04-161996-11-15Nakshatri, H., Bhat-Nakshatri, P., & Currie, R. A. (1996). Subunit Association and DNA Binding Activity of the Heterotrimeric Transcription Factor NF-Y Is Regulated by Cellular Redox. Journal of Biological Chemistry, 271(46), 28784–28791. https://doi.org/10.1074/jbc.271.46.287840021-9258, 1083-351Xhttps://hdl.handle.net/1805/18866NF-Y is a heterotrimeric transcription factor that specifically recognizes a CCAAT box motif found in a variety of eukaryotic promoter and enhancer elements. The subunit association and DNA binding properties of the NF-Y complex were examined as a function of redox state using recombinant NF-YA, NF-YB, and NF-YC subunits. Reduction of NF-YB by dithiothreitol (DTT) was essential for reconstitution of specific NF-Y CCAAT box DNA binding activity in vitro. Approximately 30% of the Escherichia coli-derived NF-YB subunit existed as intermolecular disulfide-linked dimers. NF-YB mutants in which the highly conserved cysteine residues at positions 85 and 89 had been converted to serines existed only as monomers and did not require DTT for functional NF-Y DNA binding activity. DTT was required, however, for the functional association of NF-YC with wild-type NF-YB but not with the NF-YB cysteine mutants. The cellular redox factors Ref-1 and adult T-cell leukemia-derived factor stimulated the DNA binding activity of recombinant NF-Y in the absence of DTT. Cells treated with 1-chloro-2,4-dinitrobenzene, an irreversible inhibitor of thioredoxin reductase, exhibited reduced endogenous NF-Y DNA binding activity. Together these results suggest that the cellular redox environment of mammalian cells is an important posttranscriptional regulator of NF-Y subunit association and DNA binding activities.en-USDNANF-Ycellular redoxArticle10.1074/jbc.271.46.28784