Loss of RPA1 induces Chk2 phosphorylation through a caffeine-sensitive pathway

Runa Araya, Itaru Hirai, Cheryl L. Meyerkord, Hong Gang Wang

Research output: Contribution to journalArticlepeer-review

15 Scopus citations


RPA is an important component of DNA replication, repair and recombination, but its involvement in the signaling of cell-cycle checkpoints is not well understood. In this study, we show that knockdown of RPA1 by siRNA duplexes induces ATM (Ser1981) and Chk2 (Thr68), but not Chk1 (Ser345) phosphorylation and results in p21 upregulation in HeLa cells. However, the induction of Chk2 (Thr68) phosphorylation and p21 expression by RPA1 siRNA transfection can be completely blocked by the ATM inhibitor caffeine. Moreover, transfection of siRNAs targeting ATM dramatically reduces Chk2 (Thr68) phosphorylation in RPA1 knockdown cells. Taken together, these results suggest that loss of RPA1 activates the Chk2 signaling pathway in an ATM-dependent manner.

Original languageEnglish (US)
Pages (from-to)157-161
Number of pages5
JournalFEBS Letters
Issue number1
StatePublished - Jan 3 2005

All Science Journal Classification (ASJC) codes

  • Biophysics
  • Structural Biology
  • Biochemistry
  • Molecular Biology
  • Genetics
  • Cell Biology


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