GCNA Interacts with Spartan and Topoisomerase II to Regulate Genome Stability

Dev Cell. 2020 Jan 6;52(1):53-68.e6. doi: 10.1016/j.devcel.2019.11.006. Epub 2019 Dec 12.

Abstract

GCNA proteins are expressed across eukarya in pluripotent cells and have conserved functions in fertility. GCNA homologs Spartan (DVC-1) and Wss1 resolve DNA-protein crosslinks (DPCs), including Topoisomerase-DNA adducts, during DNA replication. Here, we show that GCNA mutants in mouse and C. elegans display defects in genome maintenance including DNA damage, aberrant chromosome condensation, and crossover defects in mouse spermatocytes and spontaneous genomic rearrangements in C. elegans. We show that GCNA and topoisomerase II (TOP2) physically interact in both mice and worms and colocalize on condensed chromosomes during mitosis in C. elegans embryos. Moreover, C. elegans gcna-1 mutants are hypersensitive to TOP2 poison. Together, our findings support a model in which GCNA provides genome maintenance functions in the germline and may do so, in part, by promoting the resolution of TOP2 DPCs.

Keywords: DNA-protein crosslink (DPC) repair; DVC-1; GCNA; Spartan; SprT; Top1; Top2; germ cells; topoisomerase.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans
  • DNA Damage
  • DNA Repair
  • DNA Replication*
  • DNA Topoisomerases, Type II / genetics
  • DNA Topoisomerases, Type II / metabolism*
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Genome
  • Genomic Instability*
  • Germ Cells
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mitosis*
  • Mutation
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Spermatocytes / cytology*
  • Spermatocytes / metabolism
  • Spermatogenesis

Substances

  • DNA-Binding Proteins
  • Nuclear Proteins
  • Spartan protein, mouse
  • DNA Topoisomerases, Type II