Transcription arrest relief by S-II/TFIIS during gene expression in erythroblast differentiation.
Transcription stimulator S-II relieves RNA polymerase II (RNAPII) from transcription elongation arrest. Mice lacking the S-II gene (S-II KO mice) die at mid-gestation with impaired erythroblast differentiation, and have decreased expression of the Bcl-x gene. To understand a role of S-II in Bcl-x gene expression, we examined the distribution of transcription complex on the Bcl-x gene in S-II KO mice. The amount of RNAPII at intron 2 of the Bcl-x gene was decreased in S-II KO mice, whereas recruitment of transcription initiation factor TFIIB and RNAPII to the promoter was not decreased. Consistently, in vitro transcription analysis revealed the presence of a transcription arrest site in the Bcl-x gene intron 2, and transcription arrest at this site was overcome by S-II. Furthermore, histone acetylation on the coding region of the Bcl-x gene was decreased in S-II KO mice. In the beta(major)-globin gene, whose expression was also decreased in S-II KO mice, there were no changes in RNAPII distribution or histone acetylation, but the amount of histone H3 occupying the coding region was increased. These results suggest that S-II is involved in transcription of the Bcl-x and beta(major)-globin gene during erythroblast differentiation, by relieving transcription arrest or affecting histone modification on chromatin template.
Nagata
Makiko
M
Department of Developmental Biochemistry, Graduate School of Pharmaceutical Sciences, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Ito
Takahiro
T
Arimitsu
Nagisa
N
Koyama
Hiroshi
H
Sekimizu
Kazuhisa
K
D000107:Acetylation; D000818:Animals; D002454:Cell Differentiation; D004900:Erythroblasts / Q000166:cytology / Q000378:metabolism*; D015870:Gene Expression; D006657:Histones / Q000378:metabolism; D007438:Introns; D008099:Liver / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D012319:RNA Polymerase II / Q000378:metabolism; D014158:Transcription, Genetic; D035602:Transcriptional Elongation Factors / Q000378:metabolism*; D055544:beta-Globins / Q000235:genetics
D006657:Histones; D035602:Transcriptional Elongation Factors; D055544:beta-Globins; C018648:transcription factor S-II; D012319:RNA Polymerase II