FIG. 6.

The novel doubly spliced LTR transcript can be expressed in murine cells. pcDNA3.1ORFeHis carries a C-terminal His tag fusion of the novel ORF obtained from a GR cell cDNA preparation. After transient transfections of NIH 3T3, NMuMG, and CrFK cells with pcDNA3.1ORFeHis, 20 μg of total protein extract was separated by SDS-polyacrylamide gel electrophoresis, and the novel protein was detected using a polyclonal rabbit anti-His antibody. Lanes 1, 3, and 5 show protein extracts from nontransfected NIH 3T3, NMuMG, and CrFK cells, respectively. Lanes 2, 4, and 6 show protein extracts from transfected NIH 3T3, NMuMG, and CrFK cells, respectively. After stripping, the same blot was assayed with a mouse polyclonal anti-actin antiserum (line below). M, molecular mass marker (in kilodaltons).