Live-cell monitoring of periodic gene expression in synchronous human cells identifies Forkhead genes involved in cell cycle control

Mol Biol Cell. 2012 Aug;23(16):3079-93. doi: 10.1091/mbc.E11-02-0170. Epub 2012 Jun 27.

Abstract

We developed a system to monitor periodic luciferase activity from cell cycle-regulated promoters in synchronous cells. Reporters were driven by a minimal human E2F1 promoter with peak expression in G1/S or a basal promoter with six Forkhead DNA-binding sites with peak expression at G2/M. After cell cycle synchronization, luciferase activity was measured in live cells at 10-min intervals across three to four synchronous cell cycles, allowing unprecedented resolution of cell cycle-regulated gene expression. We used this assay to screen Forkhead transcription factors for control of periodic gene expression. We confirmed a role for FOXM1 and identified two novel cell cycle regulators, FOXJ3 and FOXK1. Knockdown of FOXJ3 and FOXK1 eliminated cell cycle-dependent oscillations and resulted in decreased cell proliferation rates. Analysis of genes regulated by FOXJ3 and FOXK1 showed that FOXJ3 may regulate a network of zinc finger proteins and that FOXK1 binds to the promoter and regulates DHFR, TYMS, GSDMD, and the E2F binding partner TFDP1. Chromatin immunoprecipitation followed by high-throughput sequencing analysis identified 4329 genomic loci bound by FOXK1, 83% of which contained a FOXK1-binding motif. We verified that a subset of these loci are activated by wild-type FOXK1 but not by a FOXK1 (H355A) DNA-binding mutant.

Publication types

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

MeSH terms

  • Base Sequence
  • Cell Cycle / genetics*
  • Cell Cycle Proteins / genetics*
  • Cell Cycle Proteins / metabolism
  • Cell Cycle Proteins / physiology
  • Cell Line, Tumor
  • Chromatin Immunoprecipitation
  • Cluster Analysis
  • Consensus Sequence
  • E2F1 Transcription Factor / genetics
  • Forkhead Transcription Factors / genetics*
  • Forkhead Transcription Factors / metabolism
  • Forkhead Transcription Factors / physiology
  • Gene Expression Regulation*
  • Gene Expression*
  • Gene Knockdown Techniques
  • Genes, Reporter
  • Humans
  • Intracellular Signaling Peptides and Proteins
  • Luciferases / biosynthesis
  • Luciferases / genetics
  • Neoplasm Proteins / genetics
  • Neoplasm Proteins / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Phosphate-Binding Proteins
  • Promoter Regions, Genetic
  • Protein Binding
  • RNA Interference
  • Single-Cell Analysis
  • Transcriptome

Substances

  • Cell Cycle Proteins
  • E2F1 Transcription Factor
  • E2F1 protein, human
  • FOXK1 protein, human
  • Forkhead Transcription Factors
  • FoxJ3 protein, human
  • GSDMD protein, human
  • Intracellular Signaling Peptides and Proteins
  • Neoplasm Proteins
  • Phosphate-Binding Proteins
  • Luciferases