Abstract Body

Glycolysis is a well-conserved cytosolic pathway that converts glucose into pyruvate, which is transported via pyruvate carrier into mitochondria and enters the TCA cycle. It was shown that in Blastocystis the second part of glycolysis is localised in mitochondria and the pyruvate carrier is missing. Therefore, for Blastocystis to perform glycolysis, there has to be another transporter for glycolytic intermediates to trespass the mitochondrial inner membrane. We aim to identify which glycolytic intermediate is transported and also to characterise the novel glycolytic transporter.

Using bioinformatics, we identified a group of Stramenopile-specific transporters which are not present in other eukaryotes. The purified proteins were used for thermostability assays to screen for potential substrates. The substrates which increased the thermostability were used in transport assays. We show that while the addition of glycolytic intermediates has no effect on the thermostability of our control proteins, it has a stabilising effect on Blastocystis-specific transporters. We also show their ability to transport glycolytic intermediates by measuring the uptake of radiolabelled substrates into proteoliposomes. It indicates that Stramenopiles adapted their transporters in order to transport glycolytic intermediates.

We show that Blastocystis transporters can bind glycolytic intermediates and are able to transport them across the membrane. Given that these transporters are Stramenopile‑specific, they could be exploited as drug targets not only for Blastocystis but also for economically important pathogens such as Saprolegnia or Phytophthora.