Fig. 5. LPR1-induced filopodia resemble filopodia produced by expression of Rif, but LPR1-induced filopodia are not attenuated by co-expression with a dominant-negative-acting Rif mutant. (A) HeLa cells were co-transfected with plasmids expressing EGFP and either myc-tagged wild-type Rif (Rif WT myc), or myc-tagged constitutively active Rif (Rif QL myc). (B) HeLa cells were co-transfected with vectors encoding for myc-tagged dominant-negative Rif (Rif TN myc) and either EGFP alone or EGFP-tagged LPR1 (EGFP-LPR1). EGFP- and myc-tagged proteins, as well as actin, were examined by fluorescent microscopy in A and B. Bars, 10 µm. (C) HeLa cells were transfected with EGFP-LPR1 and either pcDNA, Rif TN myc or myc-Cdc42 (17N). EGFP-LPR1-labeled dorsal and peripheral filopodia were counted in 25 individual cells. The data shown are means ± s.d.