The peroxisome counteracts oxidative stresses by suppressing catalase import via Pex14 phosphorylation

• Main Authors: Kanji Okumoto, Mahmoud El Shermely, Masanao Natsui, Hidetaka Kosako, Ryuichi Natsuyama, Toshihiro Marutani, Yukio Fujiki
• Format: Article
• Language: English
• Published: eLife Sciences Publications Ltd 2020-08-01
• Series: eLife
• Subjects: catalase; Pex14; peroxisomal protein import; phosphorylation; hydrogen peroxide; oxidative stress
• Online Access: https://elifesciences.org/articles/55896

Most of peroxisomal matrix proteins including a hydrogen peroxide (H2O2)-decomposing enzyme, catalase, are imported in a peroxisome-targeting signal type-1 (PTS1)-dependent manner. However, little is known about regulation of the membrane-bound protein import machinery. Here, we report that Pex14, a central component of the protein translocation complex in peroxisomal membrane, is phosphorylated in response to oxidative stresses such as H2O2 in mammalian cells. The H2O2-induced phosphorylation of Pex14 at Ser232 suppresses peroxisomal import of catalase in vivo and selectively impairs in vitro the interaction of catalase with the Pex14-Pex5 complex. A phosphomimetic mutant Pex14-S232D elevates the level of cytosolic catalase, but not canonical PTS1-proteins, conferring higher cell resistance to H2O2. We thus suggest that the H2O2-induced phosphorylation of Pex14 spatiotemporally regulates peroxisomal import of catalase, functioning in counteracting action against oxidative stress by the increase of cytosolic catalase.