Peroxisome biogenesis and dynamics in Hansenula polymorpha

Malgorzata Krygowska

Research output: ThesisThesis fully internal (DIV)

501 Downloads (Pure)


Peroxisomes are important organelles to sustain life, also in man. They are very flexible with respect to their metabolic function and readily adapt their function in relation to metabolic needs. This thesis describes studies on the development and dynamics of peroxisomes in the methylotrophic yeast Hansenula polymorpha.
In yeast, peroxisomes multiply by asymmetric fission. We observed that during fission a distinct set of peroxisomal membrane proteins (PMPs) is unevenly distributed over the mother and daughter peroxisomes. As a result the new, small organelles are formed that are fully equipped to rapidly grow and incorporate novel matrix proteins to perform their function in the new cell
Next, we studied the process of de novo peroxisome formation. Until now, pex3 cells were assumed to lack peroxisomal structures and used the ER as membrane template for de novo peroxisome creation Unexpected, we observed vesicular structures in pex3 cells that developed into normal peroxisomes upon re-introduction of Pex3. This groundbreaking discovery implies that the current models on peroxisome de novo synthesis and PMP sorting are no longer valid and require adaptation
Additionally, we studied the involvement of the H. polymorpha Pex23 protein family (Pex23 and Pex32) in peroxisome biology. We discovered that Pex32 has a major impact on organelle biogenesis, whereas Pex23 most probably stimulates de novo peroxisome formation.
Finally, we identified a bona fide homologue of S. cerevisiae Inp2 in H. polymorpha, which plays a role in peroxisome distribution over mother and daughter cells during cell division.
Original languageEnglish
QualificationDoctor of Philosophy
Awarding Institution
  • University of Groningen
  • van der Klei, Ida, Supervisor
Award date14-Apr-2014
Place of Publication[S.l.]
Print ISBNs978-90-367-6953-2
Electronic ISBNs978-90-367-6954-9
Publication statusPublished - 2014

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