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

• Tipo: Artigo em Revista Científica Internacional
• Data: 2004

Autores

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

Revista

Título: Journal of Biological Chemistry

Vol. 279

Páginas: 46573-46579

ISSN: 0021-9258

Editora: Elsevier

Indexação

ISI Web of Knowledge - 46 Citações

Scopus - 48 Citações

Outras Informações

ID Authenticus: 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.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7