title: Pex11pbeta-mediated growth and division of mammalian peroxisomes follows a maturation pathway.
abstract: Peroxisomes are ubiquitous subcellular organelles, which multiply by growth and division but can also form de novo via the endoplasmic reticulum. Growth and division of peroxisomes in mammalian cells involves elongation, membrane constriction and final fission. Dynamin-like protein (DLP1/Drp1) and its membrane adaptor Fis1 function in the later stages of peroxisome division, whereas the membrane peroxin Pex11pbeta appears to act early in the process. We have discovered that a Pex11pbeta-YFP(m) fusion protein can be used as a specific tool to further dissect peroxisomal growth and division. Pex11pbeta-YFP(m) inhibited peroxisomal segmentation and division, but resulted in the formation of pre-peroxisomal membrane structures composed of globular domains and tubular extensions. Peroxisomal matrix and membrane proteins were targeted to distinct regions of the peroxisomal structures. Pex11pbeta-mediated membrane formation was initiated at pre-existing peroxisomes, indicating that growth and division follows a multistep maturation pathway and that formation of mammalian peroxisomes is more complex than simple division of a pre-existing organelle. The implications of these findings on the mechanisms of peroxisome formation and membrane deformation are discussed.
authors.affiliation: Centre for Cell Biology and Department of Biology, University of Aveiro, Aveiro, Portugal.
authors.forename: Hannah K
authors.initials: HK
authors.lastname: Delille
authors.forename: Brigitte
authors.initials: B
authors.lastname: Agricola
authors.forename: Sofia C
authors.initials: SC
authors.lastname: Guimaraes
authors.forename: Heike
authors.initials: H
authors.lastname: Borta
authors.forename: Georg H
authors.initials: GH
authors.lastname: Lüers
authors.forename: Marc
authors.initials: M
authors.lastname: Fransen
authors.forename: Michael
authors.initials: M
authors.lastname: Schrader
mesh_terms: D000818:Animals; D019556:COS Cells; D002522:Chlorocebus aethiops; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D020675:Peroxisomes / Q000378:metabolism / Q000502:physiology* / Q000648:ultrastructure; D014162:Transfection
chemical_list: D008565:Membrane Proteins; C490453:PEX11B protein, human