Open AccessMutants of theYarrowia lipolytica PEX23Gene Encoding an Integral Peroxisomal Membrane Peroxin Mislocalize Matrix Proteins and Accumulate Vesicles Containing Peroxisomal Matrix and Membrane Proteins
Author(s) -
Trevor W. Brown,
Vladimir I. Titorenko,
Richard A. Rachubinski
Publication year - 2000
Publication title -
molecular biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.463
H-Index - 225
eISSN - 1939-4586
pISSN - 1059-1524
DOI - 10.1091/mbc.11.1.141
Subject(s) - yarrowia , peroxisome , biology , peroxisomal targeting signal , biochemistry , saccharomyces cerevisiae , microbody , membrane protein , complementation , protein targeting , mutant , fungal protein , yeast , microbiology and biotechnology , gene , membrane
pex mutants are defective in peroxisome assembly. The mutant strain pex23-1 of the yeast Yarrowia lipolytica lacks morphologically recognizable peroxisomes and mislocalizes all peroxisomal matrix proteins investigated preferentially to the cytosol. pex23 strains accumulate vesicular structures containing both peroxisomal matrix and membrane proteins. The PEX23 gene was isolated by functional complementation of the pex23-1 strain and encodes a protein, Pex23p, of 418 amino acids (47,588 Da). Pex23p exhibits high sequence similarity to two hypothetical proteins of the yeast Saccharomyces cerevisiae. Pex23p is an integral membrane protein of peroxisomes that is completely, or nearly completely, sequestered from the cytosol. Pex23p is detected at low levels in cells grown in medium containing glucose, and its levels are significantly increased by growth in medium containing oleic acid, the metabolism of which requires intact peroxisomes.