FIG 3 .

TgGAMA is a secreted micronemal protein capable of binding host cells. (A) Parasite lysate (pellet) and induced ESA fractions. ESA fractions were collected from culture supernatants after parasites were treated for 2 min at 37°C with 1% DMSO, 1% ethanol, or 1 µM BAPTA-AM. (B) Indirect immunofluorescence assay of intracellular parasites with rabbit anti-GAMA and mouse anti-MIC2 antibodies. (C) Western blot assays of material from cell binding assays. Parasite sonicate was incubated with host cells (HFF, MEF, or CHO cells), lysed in RIPA buffer, and resolved by 10% SDS-PAGE. Blots were probed with rabbit anti-GAMA, rabbit anti-MIC4, or rabbit anti-MIC5 antibodies. W4, wash 4; GAMA-full, full-length unprocessed GAMA. Asterisks indicate nonspecific bands. (D) TgGAMA mobilizes to the surface of invading parasites (top) and is capped posteriorly along with MIC2 as the tachyzoite penetrates the host cell (middle and bottom). Arrows indicate the moving junction. The values beside the blots in panels A and C are molecular sizes in kilodaltons.