9.B.437.  The ESCRT-interacting Dense Granule Protein GRA64 (GRA64) Family 

GRA64 (TGME49_202620) is a transmembrane dense granule protein of 330 aas and 2 TMSs, N- and C-terminal, on the parasitophorous vacuolar membrane (PVM) of the intracellular parasite Toxoplasma gondii.  It is partially exposed to the host cell cytoplasm in both tachyzoite and bradyzoite parasitophorous vacuoles (Mayoral et al. 2022). GRA64 interacts with components of the host endosomal sorting complexes required for transport (ESCRT) (TC# 3.A.31). Δgra64 tissue cysts, enlarged vesicular structures underneath the cyst membrane, suggesting a role for GRA64 in organizing the recruitment of ESCRT proteins and subsequent intracystic vesicle formation. There seem to be very few homologs of this protein based on NCBI BLAST searchs on 7/1/2022.