The human peroxisomal targeting signal receptor, Pex5p, is translocated into the peroxisomal matrix and recycled to the cytosol

Cell. 2001 Apr 20;105(2):187-96. doi: 10.1016/s0092-8674(01)00310-5.

Abstract

Peroxisomal targeting signals (PTSs) are recognized by predominantly cytosolic receptors, Pex5p and Pex7p. The fate of these PTS receptors following their interactions on the peroxisomal membrane with components of docking and putative translocation complexes is unknown. Using both novel and multiple experimental approaches, we show that human Pex5p does not just bind cargo and deliver it to the peroxisome membrane, but participates in multiple rounds of entry into the peroxisome matrix and export to the cytosol independent of the PTS2 import pathway. This unusual shuttling mechanism for the PTS1 receptor distinguishes protein import into peroxisomes from that into most other organelles, with the exception of the nucleus.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Cell Fractionation
  • Cell Line
  • Cytosol / chemistry
  • Cytosol / metabolism
  • Detergents / pharmacology
  • Digitonin / pharmacology
  • Endopeptidases / metabolism
  • Genes, Reporter / genetics
  • Humans
  • Immunoblotting
  • Indicators and Reagents / pharmacology
  • Kinetics
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism*
  • Octoxynol / pharmacology
  • Peroxisome-Targeting Signal 1 Receptor
  • Peroxisomes / metabolism*
  • Protein Transport / drug effects
  • Protein Transport / physiology*
  • Receptors, Cell Surface / genetics
  • Receptors, Cell Surface / metabolism*
  • Receptors, Cytoplasmic and Nuclear / metabolism*
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Transfection

Substances

  • Detergents
  • Indicators and Reagents
  • Membrane Proteins
  • Peroxisome-Targeting Signal 1 Receptor
  • Receptors, Cell Surface
  • Receptors, Cytoplasmic and Nuclear
  • Recombinant Fusion Proteins
  • peroxisomal targeting sequence receptor
  • Octoxynol
  • Endopeptidases
  • Digitonin