600 / 2019-04-20 17:57:04

Chromatin remodeling factor CHR18 interacts with replication protein RPA1A to regulate the DNA replication stress response in Arabidopsis

Arabidopsis,chromatin remodeling factor 18 (CHR18),DNA replication stress,nuclear foci,replication protein A1A (RPA1A).

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DNA replication is a fundamental process for the faithful transmission of genetic information in all living organisms. Many endogenous and environmental signals impede fork progression during DNA synthesis, which induces replication errors and DNA replication stress. Chromatin remodeling factors regulate nucleosome occupancy and the histone composition of the nucleosome in chromatin. However, whether chromatin remodeling factors are involved in the DNA replication stress response in plants is unknown.
Arabidopsis chromatin remodeling factor CHR18 is a typical nuclear-localized chromatin remodeling factor with ATPase activity. Replication protein A (RPA) is a single-stranded DNA (ssDNA)-binding heterotrimeric protein complex that plays essential roles in DNA replication. The RPA complex comprises three subunits (RPA1, RPA2, and RPA3). RPA1A is one of the five RPA1 paralogs (RPA1A, B, C, D and E) in Arabidopsis. According to the genetic analysis, the loss of function of either CHR18 or RPA1A confers a high sensitivity to DNA replication stress in Arabidopsis thaliana. CHR18 interacts with RPA1A in both yeast cells and tobacco epidermal cells. The co-expression of RPA1A and CHR18 enhances the accumulation of CHR18 in nuclear foci in plants.
Our results reveal that, during DNA replication stress in plants, RPA1A interacts with CHR18 and recruits CHR18 to nuclear foci to resolve DNA replication stress, which is important for cell propagation and root growth in Arabidopsis plants.