title: Biochemically distinct vesicles from the endoplasmic reticulum fuse to form peroxisomes.
abstract: As a rule, organelles in eukaryotic cells can derive only from pre-existing organelles. Peroxisomes are unique because they acquire their lipids and membrane proteins from the endoplasmic reticulum (ER), whereas they import their matrix proteins directly from the cytosol. We have discovered that peroxisomes are formed via heterotypic fusion of at least two biochemically distinct preperoxisomal vesicle pools that arise from the ER. These vesicles each carry half a peroxisomal translocon complex. Their fusion initiates assembly of the full peroxisomal translocon and subsequent uptake of enzymes from the cytosol. Our findings demonstrate a remarkable mechanism to maintain biochemical identity of organelles by transporting crucial components via different routes to their final destination.
authors.affiliation: Cellular Protein Chemistry, Faculty of Science, Utrecht University, NL-3584 CH Utrecht, The Netherlands. a.vanderzand@uu.nl
authors.forename: Adabella
authors.initials: A
authors.lastname: van der Zand
authors.forename: Jürgen
authors.initials: J
authors.lastname: Gent
authors.forename: Ineke
authors.initials: I
authors.lastname: Braakman
authors.forename: Henk F
authors.initials: HF
authors.lastname: Tabak
mesh_terms: D022162:Cytoplasmic Vesicles / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism; D008954:Models, Biological; D020675:Peroxisomes / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000166:cytology* / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism
chemical_list: D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins