Publication in PNAS: Pex11p fills the GAP in peroxisomal division

Researchers at the University of Groningen have shed new light onto how the division of peroxisomes is controlled. The research, which was published this week in the journal Proceedings of the National Academy of Sciences (PNAS), focused on how a protein called Pex11p regulates the division of peroxisomes in yeast and humans. Cells tightly control peroxisome division because mistakes in this process are known to cause severe human diseases.

Eukaryotic cells gather a large variety of metabolic processes into peroxisomes. The number of peroxisomes per cell is highly flexible and depends on the cellular needs. An increase in peroxisome numbers is achieved by division of pre-existing ones. Pex11p and Dnm1p are two proteins that play important yet different roles in this process. Pex11p is required for organelle elongation, the first step in peroxisome division, while the GTPase Dnm1p cuts the elongated peroxisome in two, the final act in the process. Nevertheless, how both proteins cooperate to regulate peroxisomal division was not known.

The researchers used cell biology and biochemistry to show that Pex11p acts as a GTPase activating protein (GAP) for Dnm1p. The new discovery that Pex11p controls both the initial and final steps in peroxisomal division lead the researchers to describe Pex11p as the Master regulator of peroxisomal division.

Several GAPs are known for Dnm1p-related proteins but, this is the first report for a Dnm1p specific GAP. Because organelle division is essential for cell vitality, this research could increase the understanding of how problems in organelle division lead to disease.

More information

The paper “The membrane remodeling protein Pex11p activates the GTPase Dnm1p during peroxisomal fission” will appear in the week of the 4^th of May 2015 in the Early Edition of PNAS.

For further information, contact Chris Williams or Ida van der Klei, Molecular Cell Biology, Groningen Biomolecular Sciences and Biotechnology Institute (GBB)