Saccharomyces cerevisiae Pex3p and Pex19p are required for proper localization and stability of peroxisomal membrane proteins
AUTOR(ES)
Hettema, Ewald H.
FONTE
Oxford University Press
RESUMO
The mechanisms by which peroxisomal membrane proteins (PMPs) are targeted to and inserted into membranes are unknown, as are the required components. We show that among a collection of 16 Saccharomyces cerevisiae peroxisome biogenesis (pex) mutants, two mutants, pex3Δ and pex19Δ, completely lack detectable peroxisomal membrane structures and mislocalize their PMPs to the cytosol where they are rapidly degraded. The other pexΔ mutants contain membrane structures that are properly inherited during vegetative growth and that house multiple PMPs. Even Pex15p requires Pex3p and Pex19p for localization to peroxisomal membranes. This PMP was previously hypothesized to travel via the endoplasmic reticulum (ER) to peroxisomes. We provide evidence that ER-accumulated Pex15p is not a sorting intermediate on its way to peroxisomes. Our results show that Pex3p and Pex19p are required for the proper localization of all PMPs tested, including Pex15p, whereas the other Pex proteins might only be required for targeting/import of matrix proteins.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=305556Documentos Relacionados
- Pex19p Interacts with Pex3p and Pex10p and Is Essential for Peroxisome Biogenesis in Pichia pastoris
- Human Pex19p Binds Peroxisomal Integral Membrane Proteins at Regions Distinct from Their Sorting Sequences
- Pex30p, Pex31p, and Pex32p Form a Family of Peroxisomal Integral Membrane Proteins Regulating Peroxisome Size and Number in Saccharomyces cerevisiae
- Pex17p Is Required for Import of Both Peroxisome Membrane and Lumenal Proteins and Interacts with Pex19p and the Peroxisome Targeting Signal–Receptor Docking Complex in Pichia pastoris
- Yarrowia lipolytica Cells Mutant for the Peroxisomal Peroxin Pex19p Contain Structures Resembling Wild-Type Peroxisomes