Reduced level of octamer binding transcription factor (Oct-1) is correlated with H2B histone gene repression during differentiation of HL-60 cells by all-trans retinoic acid.
To gain insight on the role of transacting factors in the regulatory mechanism of H2B histone gene expression during the differentiation of HL-60 cells by all-trans retinoic acid (retinoic acid), the binding pattern of the nuclear proteins to various elements in the human H2B histone upstream region has been investigated with DNase I footprinting and DNA mobility shift assay. The level of H2B histone mRNA was markedly reduced at 48 hr in retinoic acid-treated HL-60 cells. The H2B histone mRNA was repressed in proportion to the concentration of retinoic acid. In DNase I footprinting analysis, a nuclear factor (octamer binding transcription factor, Oct-1) bound at -42 bp (ATTTGCAT) both before and after retinoic-acid-induced differentiation of HL-60 cells. One DNA-protein complex was formed by DNA mobility shift assay, and the level of Oct-1 decreased during retinoic-acid-induced differentiation. In the cycloheximide-treated HL-60 cells, the level of Oct-1 also reduced. These results suggest that the transcriptional repression of H2B histone gene during retinoic-acid-induced differentiation in HL-60 cells may be mediated by reduced level of Oct-1.
Kim
K Y
KY
Department of Biochemistry, Chungnam National University, Daejeon, Korea.
Kweon
K R
KR
Lee
M S
MS
Kwak
S T
ST
Kim
K E
KE
Hwang
B D
BD
Lim
K
K
D001483:Base Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D002454:Cell Differentiation / Q000187:drug effects*; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I / Q000378:metabolism; D006657:Histones / Q000235:genetics*; D051863:Host Cell Factor C1; D006801:Humans; D015473:Leukemia, Promyelocytic, Acute; D008969:Molecular Sequence Data; D050811:Octamer Transcription Factor-1; D011401:Promoter Regions, Genetic; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic; D014212:Tretinoin / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
D004268:DNA-Binding Proteins; C497692:HCFC1 protein, human; D006657:Histones; D051863:Host Cell Factor C1; D050811:Octamer Transcription Factor-1; C494165:POU2F1 protein, human; D014157:Transcription Factors; D014212:Tretinoin; D004247:DNA; D003850:Deoxyribonuclease I