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The DNA‐dependent protease AtWSS1A suppresses persistent double strand break formation during replication
Author(s) -
Hacker Leonie,
Capdeville Niklas,
Feller Laura,
EnderleKukla Janina,
Dorn Annika,
Puchta Holger
Publication year - 2022
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.17848
Subject(s) - biology , dna repair , genome instability , replication protein a , dna replication , microbiology and biotechnology , genetics , dna , postreplication repair , mutant , dna damage , dna mismatch repair , gene , dna binding protein , transcription factor
Summary The protease WSS1A is an important factor in the repair of DNA‐protein crosslinks in plants. Here we show that the loss of WSS1A leads to a reduction of 45S rDNA repeats and chromosomal fragmentation in Arabidopsis. Moreover, in the absence of any factor of the RTR (RECQ4A/TOP3α/RMI1/2) complex, which is involved in the dissolution of DNA replication intermediates, WSS1A becomes essential for viability. If WSS1A loss is combined with loss of the classical (c) or alternative (a) nonhomologous end joining (NHEJ) pathways of double‐strand break (DSB) repair, the resulting mutants show proliferation defects and enhanced chromosome fragmentation, which is especially aggravated in the absence of aNHEJ. This indicates that WSS1A is involved either in the suppression of DSB formation or in DSB repair itself. To test the latter we induced DSB by CRISPR/Cas9 at different loci in wild‐type and mutant cells and analyzed their repair by deep sequencing. However, no change in the quality of the repair events and only a slight increase in their quantity was found. Thus, by removing complex DNA‐protein structures, WSS1A seems to be required for the repair of replication intermediates which would otherwise be resolved into persistent DSB leading to genome instability.