Adaptation of the cytoskeleton for pathogenicity in the malaria parasite

To ensure disease transmission, the malaria parasite undergoes multiple rounds of
metamorphosis, as it entirely alters its cell morphology to promote uptake and establishment in the
mosquito vector and human host. Two cytoskeletal components play essential roles in this process:
microtubules and actin.
Within each new ecological niche, microtubules drive the single-celled parasite’s successive cellular
transformations. Microtubules have been studied extensively and their architecture and composition are
established to be highly conserved. Using focussed ion beam milling and electron cryo-tomography, we
recently studied distinct stages in the Plasmodium falciparum life cycle. This revealed that the parasite has
microtubules which are evolved to undertake specific roles in each life cycle stage with structures that are
strikingly different from the well-studied canonical microtubules in vertebrates.
While unique microtubules drive cellular transformations, filamentous actin ensures several parasite
stages can migrate between different niches. These stages utilise a unique form of motility, termed gliding
motility, which relies on a specialised actomyosin motor system. Our recent work on actively gliding
parasites sheds light on this process and highlights novel roles of parasite actin in other cellular locations.
Together, this work provides unexpected insights into adaptations of the parasite’s cytoskeleton,
highlighting areas of novelty where the parasite has diverged from the biology of the host.