title: PAS3, a Saccharomyces cerevisiae gene encoding a peroxisomal integral membrane protein essential for peroxisome biogenesis.
abstract: Saccharomyces cerevisiae pas3-mutants are described which conform the pas-phenotype recently reported for the peroxisomal assembly mutants pas1-1 and pas2 (Erdmann, R., M. Veenhuis, D. Mertens, and W.-H Kunau, 1989, Proc. Natl. Acad. Sci. USA. 86:5419-5423). The isolation of pas3-mutants enabled us to clone the PAS3 gene by functional complementation. DNA sequence analysis revealed a 50.6-kD protein with at least one domain of sufficient length and hydrophobicity to span a lipid bilayer. To verify these predictions antibodies were raised against a truncated portion of the PAS3 coding region overexpressed in E. coli. Pas3p was identified as a 48 kD peroxisomal integral membrane protein. It is shown that a lack of this protein causes the peroxisome-deficient phenotype and the cytosolic mislocalization of peroxisomal matrix enzymes. Based on protease digestion experiments Pas3p is discussed to be anchored in the peroxisomal membrane by its amino-terminus while the bulk of the molecule is exposed to the cytosol. These findings are consistent with the possibility that Pas3p is one component of the peroxisomal import machinery.
authors.affiliation: Abteilung für Zellbiochemie, Ruhr-Universität Bochum, Federal Republic of Germany.
authors.forename: J
authors.initials: J
authors.lastname: Höhfeld
authors.forename: M
authors.initials: M
authors.lastname: Veenhuis
authors.forename: W H
authors.initials: WH
authors.lastname: Kunau
mesh_terms: D018528:ATP-Binding Cassette Transporters; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D005656:Fungal Proteins / Q000235:genetics* / Q000302:isolation & purification; D005800:Genes, Fungal; D005816:Genetic Complementation Test; D005838:Genotype; D015151:Immunoblotting; D008565:Membrane Proteins / Q000235:genetics* / Q000302:isolation & purification; D008830:Microbodies / Q000502:physiology* / Q000648:ultrastructure; D008854:Microscopy, Electron; D008961:Models, Structural; D008969:Molecular Sequence Data; D008970:Molecular Weight; D000074401:Peroxins; D010641:Phenotype; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000302:isolation & purification; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000502:physiology / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins
chemical_list: D018528:ATP-Binding Cassette Transporters; D005656:Fungal Proteins; D008565:Membrane Proteins; C070895:PEX3 protein, S cerevisiae; D000074401:Peroxins; D011994:Recombinant Proteins; C406793:SPF1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins