The Drosophila BRM complex facilitates global transcription by RNA polymerase II

Abstract

Drosophila brahma (brm) encodes the ATPase subunit of a 2 MDa complex that is related to yeast SWI/SNF and other chromatin-remodeling complexes. BRM was identi®ed as a transcriptional activator of Hox genes required for the speci®cation of body segment identities. To clarify the role of the BRM complex in the transcription of other genes, we examined its distribution on larval salivary gland polytene chromosomes. The BRM complex is associated with nearly all transcriptionally active chromatin in a pattern that is generally non-overlapping with that of Polycomb, a repressor of Hox gene transcription. Reduction of BRM function dramatically reduces the association of RNA polymerase II with salivary gland chromosomes. A few genes, such as induced heat shock loci, are not associated with the BRM complex; transcription of these genes is not compromised by loss of BRM function. The distribution of the BRM complex thus correlates with a dependence on BRM for gene activity. These data suggest that the chromatin remodeling activity of the BRM complex plays a general role in facilitating transcription by RNA polymerase II.

Parental RNA interference of genes involved in embryonic development of the western corn rootworm, Diabrotica virgifera virgifera LeConte

“…The loss of Drosophila brahma impairs overall transcription by RNA polymerase II (Pol II), suggesting a broad function for the Brahma complexes (Armstrong et al, 2002). Such roles and the clear impact of RNAi-mediated knockdown of dvvbrm suggest strongly that disruption of the dvbrm expression causes effects very early in embryonic development.…”

Interplay between chromatin remodelers and protein arginine methyltransferases

“…This is evident from immunolocalization of the BAP specific subunit, OSA, and PBAP component, polybromo, on polytene chromosomes, which show both distinct and overlapping distribution of BAP and PBAP complexes (Armstrong et al, 2002;Mohrmann et al, 2004). Knockdown of OSA using RNAi in Drosophila S2 cells depletes BAP complex and this results in G2 to M arrest, while cells lacking PBAP show no cell cycle defects.…”

Use of chromatin remodeling ATPases as RNAi targets for parental control of western corn rootworm (Diabrotica virgifera virgifera) and Neotropical brown stink bug (Euschistus heros)

“…Chromatin remodelers mobilize nucleosomes and thus change access of the transcriptional machinery to DNA (Cote et al, 1994). Chromatin remodelers may also have broader transcriptional effects on RNA polymerase II (Armstrong et al, 2002). Chromatin-remodeling ATPases are identified by a combination of SNF2 family N-terminal and Helicase conserved C-terminal domains.…”