Modification of octamer binding transcriptional factor is related to H2B histone gene repression during dimethyl sulfoxide-dependent differentiation of HL-60 cells

Transcriptional regulation of H2B histone gene during dimethyl sulfoxide (D MSO)-dependent differentiation of HL-60 cells has been investigated using D Nase I footprinting and DNA mobility shift assay. The level of histone H2B mRNA showed a slight decline at 2 days and hardly detectable at 4 days afte r DMSO treatment. H2B histone mRNA was repressed in proportion to the conce ntration of DMSO. In DNase I footprinting analysis, one nuclear factor (oct amer binding transcription factor, OTF) bound at -42 bp (octamer motif, ATT TGCAT) in undifferentiated HL-60 cells. The binding pattern of OTF was unch anged during DMSO-dependent differentiation. One protein complex (OTF) was detected by DNA mobility shift assay in undifferentiated HL-60 cells. The m obility of OTF was partially retarded during DMSO-dependent differentiation and the retardant OTF was not newly synthesized protein. These results sug gest that the posttranslational modification of OTF may be responsible for the repression of H2B histone gene during DMSO-dependent differentiation of HL-60 cells. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.