FIG. 5.

FISC physically binds to both EcR/USP and βFtz-F1. (A and B) Protein complexes identified by immunoprecipitation (IP) experiments. L57-3-11 cells were transfected with the indicated expression vectors. Cell extracts were incubated with antibody (Ab) against EcR or βFtz-F1 (A) or USP (B). The precipitated proteins were detected by immunoblotting (IB) with anti-V5 antibody. In the bottom of panel A, 50% of the inputs were loaded and subjected to Western blot analysis with the indicated antibodies. An additional protein band (asterisk) reacted to FISC antibodies, presumably representing a FISC derivative generated by using an alternative start codon. (C) Protein interactions in the fat body detected by gel mobility shift assays. Nuclear proteins were extracted from fat bodies of female mosquitoes at 6 h post-blood meal. Gel shift assays were performed with a ³²P-labeled probe corresponding to the EF fragment of the Vg promoter (Fig. 4A). FBNE, fat body nuclear extracts.