title: Lumenal peroxisomal protein aggregates are removed by concerted fission and autophagy events.
abstract: We demonstrated that in the yeast Hansenula polymorpha peroxisome fission and degradation are coupled processes that are important to remove intra-organellar protein aggregates. Protein aggregates were formed in peroxisomes upon synthesis of a mutant catalase variant. We showed that the introduction of these aggregates in the peroxisomal lumen had physiological disadvantages as it affected growth and caused enhanced levels of reactive oxygen species. Formation of the protein aggregates was followed by asymmetric peroxisome fission to separate the aggregate from the mother organelle. Subsequently, these small, protein aggregate-containing organelles were degraded by autophagy. In line with this observation we showed that the degradation of the protein aggregates was strongly reduced in dnm1 and pex11 cells in which peroxisome fission is reduced. Moreover, this process was dependent on Atg1 and Atg11.
authors.affiliation: Molecular Cell Biology; University of Groningen; Groningen, The Netherlands.
authors.forename: Selvambigai
authors.initials: S
authors.lastname: Manivannan
authors.forename: Rinse
authors.initials: R
authors.lastname: de Boer
authors.forename: Marten
authors.initials: M
authors.lastname: Veenhuis
authors.forename: Ida J
authors.initials: IJ
authors.lastname: van der Klei
mesh_terms: D001343:Autophagy; D002374:Catalase / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000378:metabolism; D009154:Mutation; D018384:Oxidative Stress; D020675:Peroxisomes / Q000378:metabolism* / Q000648:ultrastructure; D010843:Pichia / Q000166:cytology* / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D020836:Protein Structure, Quaternary; D059748:Proteolysis; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D017382:Reactive Oxygen Species; D049452:Green Fluorescent Proteins; D002374:Catalase
keywords: autophagy; fission; peroxisome; protein aggregate; yeast