PfMORN1 excision is not required for proper morphological localization of proteins markers for several major subcellular structures. Airyscan superresolution microscopy of PfMORN1 (V5) and PfAMA1 (A), PfBCP1 (B), PfGAP45 (C), and PfRON4 (D) in [2] and [1] rapa schizonts. A schematic of the localization for each marker is shown below each column. A late segmentation schizont is shown for panel A because PfAMA1 can be confidently visualized only at this stage. For the other markers, mid-segmentation schizonts are shown. Bars, 1 mm. In the absence of PfMORN1, PfAMA1 still exhibits apical localization that is typically observed prior to egress (A). Confirming that micronemal PfAMA1 staining appears very late into the segmentation process, in rapa parasites, PfMORN1 (V5) staining is observed only near the basal end of segmenting parasites when PfAMA1 staining is present. Despite being a member of the basal complex, PfMORN1 deficiency has no impact on the localization of the basal complex member PfBCP1, which forms rings around segmenting parasites in the absence of PfMORN1 (B). Similarly, in the absence of PfMORN1, PfGAP45 still surrounds segmenting daughter parasites from the apical end down to the basal complex, observed as a ring in a single z-slice (C). Finally, in the absence of PfMORN1, PfRON4 still localized as punctate dots at the apical end of the forming merozoites (D), suggesting normal morphology of rhoptries.

Moran CJ, Dvorin JD. The Basal Complex Protein PfMORN1 Is Not Required for Asexual Replication of Plasmodium falciparum. mSphere. 2021 Dec 8:e0089521.