FIG. 4.

ppUL44 dimerization and UL44-FL are required for in vivo DNA binding. (A) HEK 293 cells expressing the indicated fusion proteins were harvested 48 h after transfection, and cellular fraction collection and SDS-PAGE/Western blot analysis were performed as described in Materials and Methods. An anti-GFP MAb was used to detect the GFP fusion proteins extracted after incubation of the cells with the following buffers: S1, NP-40; S2, wash; S3, DNase I; S4, wash; S5, NaCl 2 M; S6, Laemmli buffer; and L, whole-cell lysates. (B) Images such as those in A were analyzed as described in Materials and Methods to calculate the relative amounts of the indicated GFP fusion protein present in the specified cellular fraction. The data represent the means of three independent experiments, where the amount of soluble (S1 and S2), DNA-bound (S3 to S5), and matrix-associated (S6) proteins are expressed as a percentage of the total. The data represent the means of three independent experiments.