Pex5p imports folded tetrameric catalase by interaction with pex13p

Hidenori Otera, Yukio Fujiki

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

Human catalase forms a 240-kDa tetrameric complex and degrades H 2 O 2 in peroxisomes. Human catalase is targeted to peroxisomes by the interaction of its peroxisomal targeting signal type 1 (PTS1)-like KANL sequence with the cytosolic PTS1 receptor Pex5p. We show herein that human catalase tetramers are formed in the cytoplasm and that the expression of a PTS signal on each of the four subunits is not necessary for peroxisomal transport. We previously demonstrated that a Pex5p mutant defective in binding to Pex13p, designated Pex5p(Mut234), imports typical PTS1-type proteins but not catalase. This impaired catalase import is not rescued by replacing its C-terminal KANL sequence with a typical PTS1 sequence, SKL, indicating that the failure of catalase import in Mut234-expressing cells is not due to its weak PTS1. In contrast, several enzymatically inactive and monomeric mutants of catalase are efficiently imported in Mut234-expressing cells. Moreover, trimeric chloramphenicol acetyltransferase (CAT) harboring SKL is not imported in Pex5p(Mut234)-expressing cells, but CAT-SKL trimers are transported to peroxisomes in the wild-type cells. These findings suggest that the Pex5p-Pex13p interaction likely plays a pivotal role in the peroxisomal import of folded and oligomeric proteins.

Original languageEnglish
Pages (from-to)1364-1377
Number of pages14
JournalTraffic
Volume13
Issue number10
DOIs
Publication statusPublished - Oct 1 2012

All Science Journal Classification (ASJC) codes

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

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