PRC1 associates with the hsp70i promoter and interacts with HSF2 during mitosis

Exp Cell Res. 2008 Jul 1;314(11-12):2224-30. doi: 10.1016/j.yexcr.2008.04.015. Epub 2008 May 8.

Abstract

Mitosis is a series of events leading to division of a cell by the process known as cytokinesis. Protein regulating cytokinesis 1 (PRC1) is a CDK substrate that associates with the mitotic spindle and functions in microtubule bundling. Previous studies revealed that loss of PRC1 is associated with chromosomal mis-segregation and atypical chromosome alignment. HSF2 is a DNA binding protein that we previously showed bookmarks the hsp70i gene during mitosis, an epigenetic mechanism which allows the hsp70i gene to re-establish transcriptional competence early in G1. Another study demonstrated that HSF2-/- mouse embryonic fibroblasts (MEFs) exhibit increased numbers of multinucleated cells vs. wild-type MEFs. This suggests that HSF2 is important for proper cytokinesis, but the mechanism was unknown. Here we report the existence of a direct interaction between HSF2 and PRC1. HSF2 and PRC1 associate during mitosis and co-localize during this phase of the cell cycle. PRC1 does not interact with the related protein HSF1, indicating the specificity of the HSF2-PRC1 interaction. Intriguingly, PRC1 is associated with the hsp70i promoter during mitosis. These results provide a potential mechanistic basis for the defective cytokinesis phenotype exhibited by HSF2-/- cells, as well as suggest a potential role for PRC1 in HSF2-mediated gene bookmarking.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism*
  • HSP70 Heat-Shock Proteins / genetics
  • HSP70 Heat-Shock Proteins / metabolism*
  • HeLa Cells
  • Heat-Shock Proteins / genetics
  • Heat-Shock Proteins / metabolism*
  • Humans
  • Jurkat Cells
  • Mice
  • Mitosis / physiology*
  • Promoter Regions, Genetic*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Transcription Factors / genetics
  • Transcription Factors / metabolism*
  • Two-Hybrid System Techniques

Substances

  • Cell Cycle Proteins
  • HSP70 Heat-Shock Proteins
  • Heat-Shock Proteins
  • PRC1 protein, human
  • Recombinant Fusion Proteins
  • Transcription Factors
  • HSF2 protein, human