Exploration of CTCF post-translation modifications uncovers Serine-224 phosphorylation by PLK1 at pericentric regions during the G2/M transition

Elife. 2019 Jan 24;8:e42341. doi: 10.7554/eLife.42341.

Abstract

The zinc finger CCCTC-binding protein (CTCF) carries out many functions in the cell. Although previous studies sought to explain CTCF multivalency based on sequence composition of binding sites, few examined how CTCF post-translational modification (PTM) could contribute to function. Here, we performed CTCF mass spectrometry, identified a novel phosphorylation site at Serine 224 (Ser224-P), and demonstrate that phosphorylation is carried out by Polo-like kinase 1 (PLK1). CTCF Ser224-P is chromatin-associated, mapping to at least a subset of known CTCF sites. CTCF Ser224-P accumulates during the G2/M transition of the cell cycle and is enriched at pericentric regions. The phospho-obviation mutant, S224A, appeared normal. However, the phospho-mimic mutant, S224E, is detrimental to mouse embryonic stem cell colonies. While ploidy and chromatin architecture appear unaffected, S224E mutants differentially express hundreds of genes, including p53 and p21. We have thus identified a new CTCF PTM and provided evidence of biological function.

Keywords: CTCF; PLK1; cell cycle; chromosome architecture; chromosomes; gene expression; mouse; post-translational modification.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • CCCTC-Binding Factor / chemistry
  • CCCTC-Binding Factor / metabolism*
  • Casein Kinase II / metabolism
  • Cell Cycle Proteins / metabolism*
  • Cell Proliferation
  • Chromatin
  • Conserved Sequence
  • DNA / metabolism
  • DNA Mutational Analysis
  • G2 Phase*
  • Humans
  • Interphase
  • Membrane Proteins / metabolism
  • Mice
  • Mitosis*
  • Mutation / genetics
  • Phosphorylation
  • Phosphoserine / metabolism*
  • Ploidies
  • Protein Binding
  • Protein Processing, Post-Translational*
  • Protein-Serine-Threonine Kinases / metabolism*
  • Proto-Oncogene Proteins / metabolism*
  • RNA / metabolism
  • Signal Transduction
  • Tumor Suppressor Protein p53 / metabolism
  • Up-Regulation

Substances

  • CCCTC-Binding Factor
  • Cell Cycle Proteins
  • Chromatin
  • Membrane Proteins
  • Proto-Oncogene Proteins
  • Tumor Suppressor Protein p53
  • Phosphoserine
  • RNA
  • DNA
  • Casein Kinase II
  • Protein-Serine-Threonine Kinases
  • polo-like kinase 1