Deacetylase Rpd3 Facilitates Checkpoint Adaptation by Preventing Rad53 Overactivation

Abstract

bThe DNA damage checkpoint is tightly controlled. After its activation, the checkpoint machinery is inactivated once lesions are repaired or undergoes adaptation if the DNA damage is unable to be repaired. Protein acetylation has been shown to play an important role in DNA damage checkpoint activation. However, the role of acetylation in checkpoint inactivation is unclear. Here we show that histone deacetylase Rpd3-mediated deacetylation of Rad53 plays an important role in checkpoint adaptation. Deletion of Rpd3 or inhibition of its activity impairs adaptation. RPD3 deletion also leads to a higher acetylation level and enhanced kinase activity of Rad53. Replacement of two major acetylation sites of Rad53 with arginine reduces its activity and further suppresses the adaptation defect of rpd3⌬ cells, indicating that Rpd3 facilitates adaptation by preventing Rad53 overactivation. Similar to its role in adaptation, deletion of RPD3 or inhibition of its activity also suppressed checkpoint recovery. Altogether, our findings reveal an important role of Rpd3 in promoting checkpoint adaptation via deacetylation and inhibition of Rad53.

Cmr1/WDR76 defines a nuclear genotoxic stress body linking genome integrity and protein quality control

“…To assess the impact of Cmr1 and INQ on the DNA damage checkpoint, we performed a checkpoint adaptation assay using the cdc13-1 allele, which causes uncapping of telomeres and DNA-damage checkpoint activation at the restrictive temperature 34 . We included in the assay a mutant of the INQ component Rpd3, which has previously been reported to be adaptation defective 35 . After growth at the restrictive temperature for 24 h, the number of cell bodies was counted.…”

The Role of the RPD3 Complex of Saccharomyces cerevisiae Yeast in the Activation of UV-Induced Expression of RNR Complex Genes

“…The phenotypes of rpd3Δ and sin3Δ mutants diff er due to diff erent activation of Rad53 kinase, which may be due to deacetylation of Rad53 by Rpd3 deacetylase. Our fi ndings revealed that the contribution of deacetylation of Rad53 kinase makes a signifi cant contribution to the regulation hyperactivation RNR complex after UV irradiation [32]. Based on the data obtained, we assumed that the Him1 protein is a new histone chaperone participating in the repair assembly of chromatin.…”

Tos4 mediates gene expression homeostasis through interaction with HDAC complexes independently of H3K56 acetylation

“…Many roles for Rpd3 have been described; including in control of DNA replication ( 37 , 38 , 39 ), transcriptional regulation ( 45 , 46 ) and the DNA damage response ( 47 , 48 ). Further work will therefore be required to understand how Rpd3’s role in gene expression homeostasis relates to its other functions.…”