Histone variant H2A.Z antagonizes the positive effect of the transcriptional activator CPC1 to regulate catalase-3 expression under normal and oxidative stress conditions.

Histone variant H2A.Z antagonizes the positive effect of the transcriptional activator CPC1 to regulate catalase-3 expression under normal and oxidative stress conditions.
Free Radic Biol Med. 2018 May 05;:
Authors: Dong Q, Wang Y, Qi S, Gai K, He Q, Wang Y
Abstract
In eukaryotes, deposition of the histone variant H2A.Z into nucleosomes through the chromatin remodeling complex, SWR1, is a crucial step in modulating gene transcription. Recently, H2A.Z has been shown to control the expression of responsive genes, but the underlying mechanism of how H2A.Z responds to physiological stimuli is not well understood. Here, we reveal that, in Neurospora crassa, H2A.Z is a negative regulator of catalase-3 gene, which is responsible for resistance to oxidative stress. H2A.Z represses cat-3 gene expression through direct incorporation at cat-3 locus in a SWR1 complex dependent pathway. Notably, loss of H2A.Z or SWR1 subunits leads to increased binding of a transcription factor, CPC1, at cat-3 locus. Additionally, introduction of plasmids containing gene encoding H2A.Z or SWR1 complex subunits into wild-type strains decreased CAT-3 expression, indicating that H2A.Z counteracts the positive effect of CPC1 to achieve low level cat-3 expression under non-inductive condition. Furthermore, upon oxidative stress, H2A.Z is rapidly evicted from cat-3 locus for the recruitment of CPC1, resulting in robust and full cat-3 gene expression in response to exte...

Source: Free Radical Biology and Medicine - May 5, 2018 Category: Biology Authors: Dong Q, Wang Y, Qi S, Gai K, He Q, Wang Y Tags: Free Radic Biol Med Source Type: research