The N terminus of the peroxisomal cycling receptor, Pex5p, is required for redirecting the peroxisome-associated peroxin back to the cytosol

• Type: Article in International Scientific Journal
• Date: 2004

Authors

costa-rodrigues, j (Author) Other; carvalho, af (Author) Other; gouveia, am (Author) FCNAUP; fransen, m (Author) Other; sa-miranda, c (Author) Other; azevedo, je (Author) ICBAS

Journal

Title: Journal of Biological Chemistry

Vol. 279

Pages: 46573-46579

ISSN: 0021-9258

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 46 Citations

Scopus - 48 Citations

Other information

Authenticus ID: P-000-7RQ

DOI: 10.1074/jbc.m406399200

Abstract (EN): Most newly synthesized peroxisomal matrix proteins are transported to the organelle by Pex5p, a remarkable multidomain protein involved in an intricate network of transient protein-protein interactions. Presently, our knowledge regarding the structure/function of amino acid residues 118 to the very last residue of mammalian Pex5p is quite vast. Indeed, the cargo-protein receptor domain as well as the binding sites for several peroxins have all been mapped to this region of Pex5p. In contrast, structural/functional data regarding the first 117 amino acid residues of Pex5p are still scarce. Here we show that a truncated Pex5p lacking the first 110 amino acid residues (DeltaN110-Pex5p) displays exactly the peroxisomal import properties of the full-length peroxin implying that this N-terminal domain is involved neither in cargo-protein binding nor in the docking/translocation step of the Pex5p-cargo protein complex at the peroxisomal membrane. However, the ATP-dependent export step of DeltaN110-Pex5p from the peroxisomal membrane is completely blocked, a phenomenon that was also observed for a Pex5p version lacking just the first 17 amino acid residues but not for a truncated protein comprising amino acid residues 1-324 of Pex5p. By exploring the unique properties of DeltaN110-Pex5p, the effect of temperature on the import/export kinetics of Pex5p was characterized. Our data indicate that the export step of Pex5p from the peroxisomal compartment ( in contrast with its insertion into the organelle membrane) is highly dependent on the temperature.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 7