Open AccessEvolutionary History and Activity of RNase H1-Like Proteins in Arabidopsis thaliana
Author(s) -
Jan Kuciński,
Sebastian Chamera,
Aleksandra Kmera,
M. Jordan Rowley,
Sho Fujii,
Pragya Khurana,
Marcin Nowotny,
Andrzej Wierzbicki
Publication year - 2020
Publication title -
plant and cell physiology/plant and cell physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.975
H-Index - 152
eISSN - 1471-9053
pISSN - 0032-0781
DOI - 10.1093/pcp/pcaa040
Subject(s) - rnase p , biology , rnase mrp , gene , genetics , plastid , rna , arabidopsis thaliana , ribonuclease , gene duplication , nuclear gene , mitochondrial dna , dna , microbiology and biotechnology , mutant , chloroplast
RNase H1 is an endonuclease specific toward the RNA strand of RNA:DNA hybrids. Members of this protein family are present in most living organisms and are essential for removing RNA that base pairs with DNA. It prevents detrimental effects of RNA:DNA hybrids and is involved in several biological processes. Arabidopsis thaliana has been previously shown to contain three genes encoding RNase H1 proteins that localize to three distinct cellular compartments. We show that these genes originate from two gene duplication events. One occurred in the common ancestor of dicots and produced nuclear and organellar RNase H1 paralogs. Second duplication occurred in the common ancestor of Brassicaceae and produced mitochondrial- and plastid-localized proteins. These proteins have the canonical RNase H1 activity, which requires at least four ribonucleotides for endonucleolytic digestion. Analysis of mutants in the RNase H1 genes revealed that the nuclear RNH1A and mitochondrial RNH1B are dispensable for development under normal growth conditions. However, the presence of at least one organellar RNase H1 (RNH1B or RNH1C) is required for embryonic development. The plastid-localized RNH1C affects plastid DNA copy number and sensitivity to replicative stress. Our results present the evolutionary history of RNH1 proteins in A. thaliana, demonstrate their canonical RNase H1 activity and indicate their role in early embryonic development.