<i>Toxoplasma gondii</i> AAP7 is essential for functionally connecting the IMC embedded apical annuli to the plasma membrane.

ABSTRACT: The Toxoplasma gondii cytoskeleton contains an intermediate filament network, supporting a quilt of alveolar sheets forming the inner membrane complex (IMC), undergirded by 22 subpellicular microtubules (SPMTs). Embedded within the IMC are the apical annuli: 5-6 ring-shaped pores facilitating dense granule exocytosis. Here we describe a novel apical annuli protein, AAP7. AAP7 depletion causes a severe fitness defect. In stable AAP7-depleted (ATc-resistant) parasites, LMBD3 no longer traffics to the annuli, but accumulates among the secretory organelles. This suggests AAP7 is required to traffic LMDB3 to the plasma membrane through a novel route. Moreover, it indicated that AAP7 connects plasma membrane embedded LMDB3 to the AAP proteins embedded in the IMC sutures. Functionally, AAP

SUBMITTER: Bauwens CN 

PROVIDER: S-EPMC12622062 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature