The peroxisome counteracts oxidative stresses by suppressing catalase import via Pex14 phosphorylation.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32831175.
- Also identified by DOI 10.7554/eLife.55896 and PMC identifier 7498260.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Most of peroxisomal matrix proteins including a hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>)-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 H<sub>2</sub>O<sub>2</sub> in mammalian cells. The H<sub>2</sub>O<sub>2</sub>-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 H<sub>2</sub>O<sub>2</sub>. We thus suggest that the H<sub>2</sub>O<sub>2</sub>-induced phosphorylation of Pex14 spatiotemporally regulates peroxisomal import of catalase, functioning in counteracting action against oxidative stress by the increase of cytosolic catalase.
Medical subject headings
- Catalase
- Membrane Proteins
- Oxidative Stress
- Peroxisomes
- Repressor Proteins