CENP-A Ubiquitylation Is Indispensable to Cell Viability

Dev Cell. 2019 Sep 23;50(6):683-689.e6. doi: 10.1016/j.devcel.2019.07.015.

Abstract

CENP-A is a centromere-specific histone H3 variant that epigenetically determines centromere identity, but how CENP-A is deposited at the centromere remains obscure. We previously reported that CENP-A K124 ubiquitylation, mediated by the CUL4A-RBX1-COPS8 complex, is essential for CENP-A deposition at the centromere. However, a recent report stated that CENP-A K124R mutants show no defects in centromere localization and cell viability. In the present study, we found that EYFP tagging induces additional ubiquitylation of EYFP-CENP-A K124R, which allows the mutant protein to bind to HJURP. Using a previously developed conditional CENP-A knockout system and our CENP-A K124R knockin mutant created by the CRISPR-Cas9 system, we show that the Flag-tagged or untagged CENP-A K124R mutant is lethal. This lethality is rescued by monoubiquitin fusion, indicating that CENP-A ubiquitylation is essential for viability.

Keywords: CENP-A; centromere; centromere identity; conditional knockout system; epigenetics; kinetochore; mitosis; monoubiquitin; posttranslational modifications (PTMs); ubiquitylation.

Publication types

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

MeSH terms

  • Cell Survival
  • Centromere Protein A / metabolism*
  • Female
  • Humans
  • Mutant Proteins / metabolism
  • Peptides / metabolism
  • Protein Binding
  • Ubiquitination*

Substances

  • Centromere Protein A
  • Mutant Proteins
  • Peptides