Pex19p-dependent targeting of Pex17p, a peripheral component of the peroxisomal protein import machinery

J Biol Chem. 2006 Jul 14;281(28):19417-25. doi: 10.1074/jbc.M603344200. Epub 2006 May 4.

Abstract

Pex19p is required for the topogenesis of peroxisomal membrane proteins (PMPs). Here we have demonstrated that Pex19p is also required for the peroxisomal targeting and stability of Pex17p, a peripheral component of the docking complex of the peroxisomal protein import machinery. We have demonstrated that Pex17p is associated with the peroxisomal Pex13p-Pex14p complex as well as with Pex19p. We have identified the corresponding binding sites for Pex14p and Pex19p and demonstrated that a specific loss of the Pex19p interaction resulted in mistargeting of Pex17p. We have shown that a construct consisting only of the Pex19p- and Pex14p-binding sites of Pex17p is sufficient to direct an otherwise cytosolic reporter protein to the peroxisomal membrane in a Pex19p-dependent manner. Our data show that the function of Pex19p as chaperone or import receptor is not restricted to integral membrane proteins but may also include peripheral PMPs. As a consequence of our data, the previous definition of a targeting signal for PMPs (mPTS) as a Pex19p-binding motif in conjunction with a transmembrane segment should be extended to regions comprising a Pex19p-binding motif and a peroxisomal anchor sequence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Binding Sites
  • Carrier Proteins / metabolism*
  • Cell Membrane / metabolism
  • Cytosol / metabolism
  • Membrane Proteins / metabolism*
  • Membrane Transport Proteins
  • Molecular Sequence Data
  • Peroxins
  • Peroxisomes / chemistry*
  • Protein Transport
  • Repressor Proteins / metabolism
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Signal Transduction
  • Two-Hybrid System Techniques

Substances

  • Carrier Proteins
  • Membrane Proteins
  • Membrane Transport Proteins
  • PEX13 protein, S cerevisiae
  • PEX14 protein, S cerevisiae
  • PEX17 protein, S cerevisiae
  • PEX19 protein, S cerevisiae
  • Peroxins
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins