Journal article
UBF levels determine the number of active ribosomal RNA genes in mammals
E Sanij, G Poortinga, K Sharkey, S Hung, TP Holloway, J Quin, E Robb, LH Wong, WG Thomas, V Stefanovsky, T Moss, L Rothblum, KM Hannan, GA McArthur, RB Pearson, RD Hannan
Journal of Cell Biology | Published : 2008
Abstract
In mammals, the mechanisms regulating the number of active copies of the ∼200 ribosomal RNA (rRNA) genes transcribed by RNA polymerase I are unclear. We demonstrate that depletion of the transcription factor upstream binding factor (UBF) leads to the stable and reversible methylation-independent silencing of rRNA genes by promoting histone H1 - induced assembly of transcriptionally inactive chromatin. Chromatin remodeling is abrogated by the mutation of an extracellular signal-regulated kinase site within the high mobility group box 1 domain of UBF1, which is required for its ability to bend and loop DNA in vitro. Surprisingly, rRNA gene silencing does not reduce net rRNA synthesis as transc..
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Awarded by National Heart, Lung, and Blood Institute
Funding Acknowledgements
This work was supported by grants from the National Health and Medical Research Council ( NHMRC) of Australia and the Cancer Council Victoria to R. D. Hannan, R. B. Pearson, and G. A. McArthur and by a National Institutes of Health grant ( 5R01HL077814 USA) to L. Rothblum. R. D. Hannan, R. B. Pearson, and G. A. McArthur were supported by NHMRC fellowships.