Direct host-parasite interaction occurs at the cytoplasmic faces of the parasitophorous vacuole membrane (PVM) and the host endoplasmic reticulum (ER) membrane via GRA3 and host CAMLG association. Direct insertion of GRA3 ER retrieval motif into the host ER membrane contributes to the host ER recruitment to the PVM. Homodimer (Probable). Interacts (via N-terminus) with human host CAMLG (via N-terminus). Located in dense granules of tachyzoites. Upon infection, secreted to the PVM. The KKXX motif functions as an ER retrieval signal that rationalizes association with PVM and the host cell ER. Chimeric cDNA, matches the N-terminus. Truncated N-terminus. Chimeric cDNA, matches the N-terminus.