title: A subtle interplay between three Pex11 proteins shapes de novo formation and fission of peroxisomes.
abstract: The organization of eukaryotic cells into membrane-bound compartments must be faithfully sustained for survival of the cell. A subtle equilibrium exists between the degradation and the proliferation of organelles. Commonly, proliferation is initiated by a membrane remodeling process. Here, we dissect the function of proteins driving organelle proliferation in the particular case of peroxisomes. These organelles are formed either through a growth and division process from existing peroxisomes or de novo from the endoplasmic reticulum (ER). Among the proteins involved in the biogenesis of peroxisomes, peroxins, members of the Pex11 protein family participate in peroxisomal membrane alterations. In the yeast Saccharomyces cerevisiae, the Pex11 family consists of three proteins, Pex11p, Pex25p and Pex27p. Here we demonstrate that yeast mutants lacking peroxisomes require the presence of Pex25p to regenerate this organelle de novo. We also provide evidence showing that Pex27p inhibits peroxisomal function and illustrate that Pex25p initiates elongation of the peroxisomal membrane. Our data establish that although structurally conserved each of the three Pex11 protein family members plays a distinct role. While ScPex11p promotes the proliferation of peroxisomes already present in the cell, ScPex25p initiates remodeling at the peroxisomal membrane and ScPex27p acts to counter this activity. In addition, we reveal that ScPex25p acts in concert with Pex3p in the initiation of de novo peroxisome biogenesis from the ER.
authors.affiliation: University of Vienna, Max F. Perutz Laboratories, Center for Molecular Biology, Department of Biochemistry and Cell Biology, Dr. Bohr-Gasse 9, Vienna, Austria.
authors.forename: Anja
authors.initials: A
authors.lastname: Huber
authors.forename: Johannes
authors.initials: J
authors.lastname: Koch
authors.forename: Friedrich
authors.initials: F
authors.lastname: Kragler
authors.forename: Cécile
authors.initials: C
authors.lastname: Brocard
authors.forename: Andreas
authors.initials: A
authors.lastname: Hartig
mesh_terms: D015153:Blotting, Western; D004721:Endoplasmic Reticulum / Q000378:metabolism / Q000648:ultrastructure; D004926:Escherichia coli / Q000235:genetics; D015870:Gene Expression; D049452:Green Fluorescent Proteins / Q000235:genetics; D007425:Intracellular Membranes / Q000378:metabolism / Q000648:ultrastructure; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D019301:Oleic Acid / Q000494:pharmacology; D053141:Organelle Size; D000074401:Peroxins; D020675:Peroxisomes / Q000378:metabolism* / Q000648:ultrastructure; D010957:Plasmids; D021381:Protein Transport; D060888:Real-Time Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
chemical_list: D008565:Membrane Proteins; C092128:PEX11 protein, S cerevisiae; C475282:PEX25 protein, S cerevisiae; D000074401:Peroxins; C483323:Pex27 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D019301:Oleic Acid