FIG. 5.

Effects on cell growth and cap-dependent translation of knocking down the eIF4Es in Giardia. Giardia WBI trophozoites transfected with in vitro transcripts from the empty vector pC631neo (A), the Giardia eIF4E1 antisense-ribozyme construct pC631neo4E1RZ (B), and the Giardia eIF4E2 antisense-ribozyme construct pC631neo4E2RZ (C) were incubated at 37°C in culture medium containing G418. Cell growth was monitored daily for up to 5 days. The insets show the intracellular mRNA levels estimated by semiquantitative RT-PCR after 1 day of incubation. RT-PCR quantitation of NADH oxidase mRNA (NADHox) was included as a control. (D) A luciferase transcript capped with m⁷GpppG was electroporated into the ribozyme-transfected cells mentioned above. The luciferase activities thus expressed were monitored 4 h thereafter and are presented with the activity in pC631neo-transfected cells designated as 100%. RLU, relative light units.