Phospholipase C-related catalytically inactive protein participates in the autophagic elimination of Staphylococcus aureus infecting mouse embryonic fibroblasts

Kae Harada-Hada, Kana Harada, Fuminori Kato, Junzo Hisatsune, Isei Tanida, Michinaga Ogawa, Satoshi Asano, Motoyuki Sugai, Masato Hirata, Takashi Kanematsu

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5 Citations (Scopus)

Abstract

Autophagy is an intrinsic host defense system that recognizes and eliminates invading bacterial pathogens. We have identified microtubule- associated protein 1 light chain 3 (LC3), a hallmark of autophagy, as a binding partner of phospholipase C-related catalytically inactive protein (PRIP) that was originally identified as an inositol trisphosphatebinding protein. Here, we investigated the involvement of PRIP in the autophagic elimination of Staphylococcus aureus in infected mouse embryonic fibroblasts (MEFs). We observed significantly more LC3-positive autophagosome-like vacuoles enclosing an increased number of S. aureus cells in PRIP-deficient MEFs than control MEFs, 3 h and 4.5 h post infection, suggesting that S. aureus proliferates in LC3-positive autophagosome-like vacuoles in PRIP-deficient MEFs. We performed autophagic flux analysis using an mRFP-GFP-tagged LC3 plasmid and found that autophagosome maturation is significantly inhibited in PRIP-deficient MEFs. Furthermore, acidification of autophagosomes was significantly inhibited in PRIP-deficient MEFs compared to the wild-type MEFs, as determined by LysoTracker staining and time-lapse image analysis performed using mRFP-GFP-tagged LC3. Taken together, our data show that PRIP is required for the fusion of S. aureus-containing autophagosome-like vacuoles with lysosomes, indicating that PRIP is a novel modulator in the regulation of the innate immune system in non-professional phagocytic host cells. Copyright:

Original languageEnglish
Article numbere98285
JournalPloS one
Volume9
Issue number5
DOIs
Publication statusPublished - May 27 2014

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All Science Journal Classification (ASJC) codes

  • Biochemistry, Genetics and Molecular Biology(all)
  • Agricultural and Biological Sciences(all)
  • General

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