title: Pex7p translocates in and out of peroxisomes in Saccharomyces cerevisiae.
abstract: Pex7p is the soluble receptor responsible for importing into peroxisomes newly synthesized proteins bearing a type 2 peroxisomal targeting sequence. We observe that appending GFP to Pex7p's COOH terminus shifts Pex7p's intracellular distribution from predominantly cytosolic to predominantly peroxisomal in Saccharomyces cerevisiae. Cleavage of the link between Pex7p and GFP within peroxisomes liberates GFP, which remains inside the organelle, and Pex7p, which exits to the cytosol. The reexported Pex7p is functional, resulting in import of thiolase into peroxisomes and improved growth of the yeast on oleic acid. These results support the "extended shuttle" model of peroxisome import receptor function and open the way to future studies of receptor export.
authors.affiliation: Mount Sinai School of Medicine, New York, NY 10029, USA.
authors.forename: Devi M
authors.initials: DM
authors.lastname: Nair
authors.forename: P Edward
authors.initials: PE
authors.lastname: Purdue
authors.forename: Paul B
authors.initials: PB
authors.lastname: Lazarow
mesh_terms: D003593:Cytoplasm / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D019301:Oleic Acid / Q000378:metabolism; D000074437:Peroxisomal Targeting Signal 2 Receptor; D020675:Peroxisomes / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: C082902:PEX7 protein, S cerevisiae; D000074437:Peroxisomal Targeting Signal 2 Receptor; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; D019301:Oleic Acid