Peroxisomal membrane contact sites in the yeast Hansenula polymorpha

Arman Aksit

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Abstract

The cell is the fundamental structural and functional unit of all living organisms. The eukaryotic cells contain a nucleus (which contains genetic material) and membrane-enclosed organelles. These organelles enable cell to isolate cellular biochemical processes by creating optimal physical conditions which increase the efficiency of these reactions.
One group of organelles are peroxisomes which are involved in a range of metabolic and non-metabolic pathways. In yeast, these organelles grow by the incorporation of membrane and matrix compounds. However, how peroxisomes acquire membrane lipids is not fully understood. Recent findings show that lipid transport between organelles could be achieved at Membrane Contact Sites (MCSs), the regions where two membranes come into close proximity.
Here we studied the role of peroxisomal MCSs in peroxisomal membrane development in the yeast Hansenula polymorpha.
Our data show that on peroxisome repressing growth conditions (i.e. glucose), peroxisomes associate with the endoplasmic reticulum (ER), whereas upon growth on peroxisome inducing conditions (i.e. methanol), these organelles associate also with the vacuole. We also show that simultaneous loss of the components/regulators of peroxisomal contacts with the ER and vacuole blocks peroxisome membrane growth; whereas the loss of the components of the same contact (i.e. only ER or vacuole) does not. Finally, we show that the peroxisomal membrane development defects of the mutant cells is restored by the expression of an artificial ER-peroxisome linker protein. Thus, our data suggest that peroxisomes may acquire their membrane lipids at peroxisomal MCSs.
Translated title of the contributionPeroxisomale membraan contacten in de gist Hansenula polymorpha
Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • University of Groningen
Supervisors/Advisors
  • van der Klei, Ida, Supervisor
  • Reggiori, Fulvio, Assessment committee
  • Kok, Jan, Assessment committee
  • Wösten, H. A. B., Assessment committee, External person
Award date4-Jun-2018
Place of Publication[Groningen]
Publisher
Print ISBNs978-94-034-0637-4
Electronic ISBNs978-94-034-0638-1
Publication statusPublished - 2018

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