Figure 7From: Translation of MMTV Gag requires nuclear events involving splicing motifs in addition to the viral Rem protein and RmRERem, the RmRE and natural splice donor and acceptor sequences rescue Gag expression. A) Schematic representation of the MMTV infectious molecular clone (pHyb-Mtv) and the two subviral clones created (LTRgag and LTR+SA). LTR, long terminal repeat; SD, splice donor; SA, splice acceptor, RmRE, Rem response element. gag, pro, pol, env, sag are the viral genes. Expression of Gag from pLTRgag B) or pLTR+SA C) was assayed in 293T cells by pulse labeling and immunoprecipitating with an MMTV anti-CA antibody in the presence or absence of GFP-Rem. Transfection of pHyb-Mtv served as a positive control. '-' lanes were transfected with GFP to equilibrate the plasmid load. β-catenin was used as a cellular control. Expression of GFP and GFP-Rem was visualized by immunoblotting with an anti-GFP antibody in pLTRgag D) or pLTR+SA E) transfected cells. Pr77gag, the Gag precursor (77 KDa), β-catenin (98 KDa), GFP-Rem (66 KDa), GFP-RemSP (40 KDa) and GFP (27 KDa). Gag levels from the LTRgag F) and LTR+SA G) were quantified relative to β-catenin. Data are average of three independent transfections ± SD.Back to article page