FIG. 6.

F protein expression as a function of amount of transfected DNA. Cos cells were transfected with vector (SVL) or increasing amounts of wild-type F DNA (WT). Vector DNA (pSVL) was added to each transfection such that the total DNA was at 1 μg. The ratios of wild-type and pSVL DNAs are shown at the top of panel A. The amounts of F protein cDNA used in each transfection are shown on the x axis in panel B. Transfected cells were radioactively labeled with [³⁵S]methionine and [³⁵S]cysteine for 4 h at approximately 48 h posttransfection and then subjected to a nonradioactive chase for 4 h. Cell extracts were precipitated with anti-Ftail antibody, and the resulting precipitated proteins were resolved on 10% polyacrylamide gels in the presence of reducing agent (β-mercaptoethanol [A]). (B) Quantitation by a densitometer of the total F protein present in each lane.