Polo-like kinase 1 phosphorylates and regulates Bcl-xL during pironetin-induced apoptosis

Y. Tamura, S. Simizu, M. Muroi, S. Takagi, M. Kawatani, N. Watanabe, H. Osada

Research output: Contribution to journalArticlepeer-review

35 Citations (Scopus)


Bcl-xL, an anti-apoptotic Bcl-2 family member protein, contributes to the resistance against chemotherapies such as tubulin-binder treatment in many human tumors. Although Bcl-xL is phosphorylated after tubulin-binder treatment, the role of the phosphorylation and its responsible kinase(s) are poorly understood. Here, we identified Plk1 (polo-like kinase 1) as a Bcl-xL kinase. Same location of Bcl-xL and Plk1 was revealed by immunocytochemical analyses at M-phase in situ. Plk1 phosphorylates Bcl-xL in vitro, and we identified Plk1 phosphorylation sites in Bcl-xL. When all of these phosphorylation sites were substituted to alanines, the anti-apoptotic activity of the Bcl-xL mutant against the apoptosis induced by pironetin, but not against ultraviolet-induced apoptosis, was increased. These observations suggest that Plk1 is a regulator of Bcl-xL phosphorylation and controls the anti-apoptotic activity of Bcl-xL during pironetin-induced apoptosis.

Original languageEnglish
Pages (from-to)107-116
Number of pages10
Issue number1
Publication statusPublished - 2009 Jan 8
Externally publishedYes


  • Apoptosis
  • Bcl-x
  • Phosphorylation
  • Pironetin
  • Plk1

ASJC Scopus subject areas

  • Molecular Biology
  • Genetics
  • Cancer Research


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