Figure 9

Identification of a gammaretroviral CTE (γ-CTE) in pol . (A) Secondary structure model of the minimal pol RNA fragment that stimulates Pr65^Gag production. This structure includes a loop with the NXF1-binding motif (AAGACA) found in the MPMV/MLV CTE (identical for both viruses). Nucleotides that were mutated to generate γ-CTE^mut (ATCGCT) are highlighted in red. In (B) and (C), HEK293T cells were transfected with expression plasmids for gag, gag-pol, gag with 4 copies of either wild-type or mutant γ-CTE, NXF1, and NXT, as indicated. Cell lysate was harvested 48 hrs later and probed with anti-CA antibody and anti-β-actin antibody. Similar results were obtained with identical constructs from MLV and XMRV. A representative experiment with MLV derived constructs is shown.