Budding yeast Rad51: a paradigm for how phosphorylation and intrinsic structural disorder regulate homologous recombination and protein homeostasis

Abstract

The RecA-family recombinase Rad51 is the central player in homologous recombination (HR), the faithful pathway for repairing DNA double-strand breaks (DSBs) during both mitosis and meiosis. The behavior of Rad51 protein in vivo is fine-tuned via posttranslational modifications conducted by multiple protein kinases in response to cell cycle cues and DNA lesions. Unrepaired DSBs and ssDNA also activate Mec1ATR and Tel1ATM family kinases to initiate the DNA damage response (DDR) that safeguards genomic integrity. Defects in HR and DDR trigger genome instability and result in cancer predisposition, infertility, developmental defects, neurological diseases or premature aging. Intriguingly, yeast Mec1ATR- and Tel1ATM-dependent phosphorylation promotes Rad51 protein stability during DDR, revealing how Mec1ATR can alleviate proteotoxic stress. Moreover, Mec1ATR- and Tel1ATM-dependent phosphorylation also occurs on DDR-unrelated proteins, suggesting that Mec1ATR and Tel1ATM have a DDR-independent function in protein homeostasis. In this minireview, we first describe how human and budding yeast Rad51 are phosphorylated by multiple protein kinases at different positions to promote homology-directed DNA repair and recombination (HDRR). Then, we discuss recent findings showing that intrinsic structural disorder and Mec1ATR/Tel1ATM-dependent phosphorylation are coordinated in yeast Rad51 to regulate both HR and protein homeostasis.

Complete Genome Sequences and Genome-Wide Characterization of Trichoderma Biocontrol Agents Provide New Insights into their Evolution and Variation in Genome Organization, Sexual Development, and Fungal-Plant Interactions

“…Isolation of genomic DNA and RNA, as well as PacBio single-molecular real-time (SMRT) genome sequencing and assembly, were carried out as described previously ( 21 , 38 , 88 ). Oxford Nanopore direct DNA library preparation and sequencing were performed at the Genomic Core Lab of the Institute of Molecular Biology, Academia Sinica.…”

Differences in RAD51 transcriptional response and cell cycle dynamics reveal varying sensitivity to DNA damage among Arabidopsis thaliana root cell types

“…This accumulation of RAD51 at the broken strand overhang (Flott et al ., 2011; Biedermann et al ., 2017; Da Ines et al ., 2022) facilitates the search for a homologous donor template (Hicks et al ., 2011; Coïc et al ., 2011; Meschichi et al ., 2022). The activity of RAD51 is tightly regulated at the post-translational level, serving as a substrate of multiple kinases in human (Sørensen et al ., 2005; Chabot et al ., 2019; Woo et al ., 2021) and budding yeasts (Flott et al ., 2011; Woo et al ., 2020, 2021). Although RAD51 phosphorylation by the cyclin kinase CDKB1-CYCB1 complex was reported in vitro for A. thaliana , its exact function remains elusive.…”

Differences in RAD51 transcriptional response and cell cycle dynamics reveal varying sensitivity to DNA damage among Arabidopsis thaliana root cell types

“…This accumulation of RAD51 at the broken strand overhang (Flott et al ., 2011; Biedermann et al ., 2017; Da Ines et al ., 2022) facilitates the search for a homologous donor template (Coïc et al ., 2011; Hicks et al ., 2011; Meschichi et al ., 2022). The activity of RAD51 is tightly regulated at the post‐translational level, serving as a substrate of multiple kinases in human (Sørensen et al ., 2005; Chabot et al ., 2019; Woo et al ., 2021) and budding yeasts (Flott et al ., 2011; Woo et al ., 2020, 2021). Although RAD51 phosphorylation by the cyclin kinase CDKB1–CYCB1 complex was reported in vitro for Arabidopsis, its exact function remains elusive.…”