Inari Kursula lab
paper in press

Paper on Plasmodium actin II accepted for publication

Andrea's paper on the structure and cellular localization of malaria parasite actin II was accepted for publication in PLoS Pathogens today! The work was a huge long-term collaborative effort between our lab and the lab of Inga Sidén-Kiamos at IMBB-FORTH, Heraklion, Crete, and that of Peter Rosenthal at the Francis Crick Institute, London, UK.

Actin II structure
Andrea Lopez

Main content

Malaria is a major global health problem, caused by parasites of the genus Plasmodium that belong to the phylum Apicomplexa. More than 600000 people die annually from nearly 250 million malaria cases registered worldwide. In contrast to other apicomplexan parasites, Plasmodium spp. encode two actin isoforms. While actin I is part of the glideosome complex, essential for locomotion, actin II is present in the mosquito stages, where it has functions in gametogenesis and in the oocyst. The exact function of actin II is still unclear, and information at the molecular level is limited. We show here that actin II is associated with the nucleus in gametocytes and zygotes and performs specific functions requiring both long filaments and fine-tuning by methylation of histidine 73. We determined the structures of the filamentous form of actin II at near-atomic resolution and characterized its polymerization properties in vitro. Our study provides a molecular basis for the differences between actins of the malaria parasite and humans, as well as between the two parasite actin isoforms. Furthermore, the in vivo studies provide insights into the function of actin II in the parasite.

Lopez AJ, Andreadaki M, Vahokoski J, Deligianni E, Calder LJ, Camerini S, Freitag A, Bergmann U, Rosenthal PB, Sidén-Kiamos I & Kursula I (2022) Structure and function of Plasmodium actin II in the parasite mosquito stages. Preprint available on bioRxivhttps://doi.org/10.1101/2022.11.22.517348.