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Molecular characterization of the PEX5 gene encoding peroxisomal targeting signal 1 receptor from the methylotrophic yeast Pichia methanolica
Author(s) -
Ito Takashi,
Fujimura Shuki,
Matsufuji Yoshimi,
Miyaji Tatsuro,
Nakagawa Tomoyuki,
Tomizuka Noboru
Publication year - 2007
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/yea.1484
Subject(s) - peroxisomal targeting signal , peroxisome , biology , biochemistry , yeast , pichia pastoris , pichia , gene , isozyme , enzyme , recombinant dna
In this study, we describe the molecular characterization of the PEX5 gene encoding the peroxisomal targeting signal 1 (PTS1) receptor from the methylotrophic yeast Pichia methanolica . The P. methanolica PEX5 ( PmPEX5 ) gene contains a open reading frame corresponding to a gene product of 646 amino acid residues, and its deduced amino acid sequence shows a high similarity to those of Pex5ps from other methylotrophic yeasts. Like other Pex5ps, the PmPex5p possesses seven repeats of the TPR motif in the C‐terminal region and three WXXXF/Y motifs. A strain with the disrupted PEX5 gene ( pex5Δ ) lost its ability to grow on peroxisome‐inducible carbon sources, methanol and oleate, but grew normally on glucose and glycerol. Disruption of PmPEX5 caused a drastic decrease in peroxisomal enzyme activities and mislocalization of GFP–PTS1 and some peroxisomal methanol‐metabolizing enzymes in the cytosol. Expression of the PmPEX5 gene was regulated by carbon sources, and it was strongly expressed by peroxisome‐inducible carbon sources, especially methanol. Taken together, these findings show that PmPex5p has an essential physiological role in peroxisomal metabolism of P. methanolica , including methanol metabolism, and in peroxisomal localization and activation of methanol‐metabolizing enzymes, e.g. AOD isozymes, DHAS and CTA. Copyright © 2007 John Wiley & Sons, Ltd.