The B-WICH chromatin-remodelling complex facilitates the binding of c-Myc and histone acetyl transferases and regulates RNA pol III transcription
(English)Manuscript (preprint) (Other academic)
Transcription of the 5S rRNA genes and 7SL genes by RNA polymerase III is necessary for cell growth and proliferation. The chromatin-remodelling complex B-WICH is associated with these genes, and siRNA-silencing of one component, the WSTF protein, reduces the level of transcription. However, the molecular mechanism is unclear. We show here that the role of B-WICH is to promote the binding of RNA polymerase III and RNA polymerase III factors, TFIIIA, TFIIIB and TFIIIC. WSTF knock down by siRNA resulted in a decreased recruitment of these initiation factors and, consequently, RNA polymerase III, to promoters. In addition, B-WICH induced a local alteration of the chromatin structure around the 5S rRNA and 7SL RNA genes, leading to a reduced acetylation of histone H3, in particular H3K9-Ac. A reduction in the level of WSTF also caused a loss of c-myc binding to the genes. We propose a model in which B-WICH complex is required to maintain an open chromatin structure around these RNA polymerase III genes, a prerequisite for other factors to associate at the gene.
B-WICH, chromatin-remodelling, c-Myc, polymerase III, transcription
Research subject Cell Biology
IdentifiersURN: urn:nbn:se:su:diva-75269OAI: oai:DiVA.org:su-75269DiVA: diva2:515407