The Histone Chaperones ASF1 and CAF-1 Promote MMS22L-TONSL-Mediated Rad51 Loading onto ssDNA during Homologous Recombination in Human Cells. Academic Article uri icon

Overview

abstract

  • The access-repair-restore model for the role of chromatin in DNA repair infers that chromatin is a mere obstacle to DNA repair. However, here we show that blocking chromatin assembly, via knockdown of the histone chaperones ASF1 or CAF-1 or a mutation that prevents ASF1A binding to histones, hinders Rad51 loading onto ssDNA during homologous recombination. This is a consequence of reduced recruitment of the Rad51 loader MMS22L-TONSL to ssDNA, resulting in persistent RPA foci, extensive DNA end resection, persistent activation of the ATR-Chk1 pathway, and cell cycle arrest. In agreement, histones occupy ssDNA during DNA repair in yeast. We also uncovered DNA-PKcs-dependent DNA damage-induced ASF1A phosphorylation, which enhances chromatin assembly, promoting MMS22L-TONSL recruitment and, hence, Rad51 loading. We propose that transient assembly of newly synthesized histones onto ssDNA serves to recruit MMS22L-TONSL to efficiently form the Rad51 nucleofilament for strand invasion, suggesting an active role of chromatin assembly in homologous recombination.

publication date

  • February 22, 2018

Research

keywords

  • Cell Cycle Proteins
  • DNA, Single-Stranded
  • DNA-Binding Proteins
  • Homologous Recombination
  • Molecular Chaperones
  • NF-kappa B
  • Nuclear Proteins
  • Rad51 Recombinase

Identity

PubMed Central ID

  • PMC5843376

Scopus Document Identifier

  • 85042317378

Digital Object Identifier (DOI)

  • 10.1016/j.molcel.2018.01.031

PubMed ID

  • 29478807

Additional Document Info

volume

  • 69

issue

  • 5