FIGURE 7.

xSLBP1 does not stimulate CSFV or PV IRES reporters. (A) m⁷G-capped Luc-MS2 (m⁷G-Luc) or ApG capped CSFV IRES-containing Luc-MS2 (CSFV-Luc) mRNAs were co-injected with β-Gal mRNA into stage VI oocytes expressing MS2-U1A or MS2-xSLBP1. Luciferase activity was normalized to β-galactosidase activity and the fold activation over MS2-U1A was plotted. The average of at least three independent experiments is shown. (B) Tethered function analysis was performed as in A except that ApG-capped PV IRES-containing Luc-MS2 (PV-Luc) was used. The average of seven independent experiments is shown. (C) Yeast two-hybrid assay in MaV99 strain using hSLBP or xSLBP1 fused to GAL4-DB and eIF4E, IRP1, or eIF3h fused to GAL4-AD. Transformed colonies were diluted and plated on selective media lacking histidine and containing 25 mM 3-AT.