FIG. 2.

Hsp72 dosage-dependent stimulation of MV minireplicon CAT reporter gene expression. Cell monolayers were transfected in duplicate with plasmids directing the expression of minigenomic RNA, transcripts for N, P, and L proteins, and an Hsp72 fusion protein containing the VSV G protein epitope. The histogram indicates average CAT activity in transfections with 1.0, 2.5, or 5.0 μg of the Hsp72 expression plasmid pT7VSV-Hsp72 relative to CAT activity in transfections lacking the Hsp72 expression plasmid. The average CAT activity in the latter was defined as 1.0. Transfections lacking the L protein expression plasmid were used as negative controls (neg). Corresponding chromatograms of CAT reaction products visualized under UV light are shown. Western blot analysis of cell extracts used for CAT assays was done with a monoclonal antibody recognizing either Hsp72-specific epitopes (α-Hsp), the VSV G protein tag of transgenic Hsp72 (α-VSV-G), or the MV N protein (α-N). The positions of molecular size markers are indicated to the right (kilodaltons).