Jr. Davie et Lc. Murphy, INHIBITION OF TRANSCRIPTION SELECTIVELY REDUCES THE LEVEL OF UBIQUITINATED HISTONE H2B IN CHROMATIN, Biochemical and biophysical research communications, 203(1), 1994, pp. 344-350
The effect of inhibiting transcription and/or replication on the stead
y state levels of the ubiquitinated histone isoforms was investigated.
We show that treatment of chinese hamster ovary (CHO), monkey kidney
(COS), human endometrial carcinoma (Hec-50 and Ishikawa) cells with ac
tinomycin D and 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole, inhi
bitors of heterogeneous nuclear RNA synthesis, selectively reduced the
levels of ubiquitinated (u) H2B, but not uH2A, uH2A.Z, polyubiquitina
ted H2A or a novel ubiquitinated histone species, in the chromatin of
these cells. The level of the ubiquitinated histones was not affected
when synthesis of DNA was arrested. These results show that, in genera
l, maintenance of the levels of uH2B in chromatin is dependent upon on
going transcription. (C) 1994 Academic Press, Inc.