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bioRxiv · 10.64898/2026.07.14.737759

Actin-related protein Alp1 governs malaria parasite motility and transmission

Kobayashi, Y.·Busse, C.·Binder, A.·Moll, A.·Frischknecht, F.·Douglas, R. G.
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Abstract

Motility of the malaria-causing parasite Plasmodium is essential for transmission to and from mosquitoes, with the turnover of actin filaments being a central feature of productive cell movement. Actin-related proteins (Arps) are known to play critical roles in motility, trafficking and chromatin remodelling. Here, we show that the actin-like protein 1 (Alp1), an apicomplexan Arp, is essential for Plasmodium ookinete motility and establishing of infection in mosquitoes. We identified an insertion region in subdomain 4 that contributes to Alp1 function in ookinetes and show novel actin filament structures in ookinetes. A combination of gene deletion and actin filament recognizing chromobody expression revealed a role of Alp1 in promoting actin filament turnover in ookinetes. We have thus identified a novel Arp that has evolved a specialist function to regulate actin dynamics, govern malaria parasite motility and facilitate malaria transmission.

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Kobayashi, Y., Busse, C., Binder, A., Moll, A., Frischknecht, F., Douglas, R. G.. 2026-07-15. Actin-related protein Alp1 governs malaria parasite motility and transmission. https://doi.org/10.64898/2026.07.14.737759

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