Effects of Fz1/2 C-Tail Mutations on Subcellular Localization and PCP Activity

<p>(A) Sequence alignment of Fz1 and Fz2 C-tails. Note high degree of conservation within the membrane proximal shared portion of the Fz1 and Fz2 C-tails. The respective mutations generated and analyzed are indicated above the sequence (see also <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020158#pbio-0020158-t001" target="_blank">Table 1</a> for complete data set). As in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020158#pbio-0020158-g002" target="_blank">Figures 2</a> and <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020158#pbio-0020158-g003" target="_blank">3</a>, <i>dpp-Gal4</i> was used to drive expression of the respective mutants, and these were detected by anti-Myc staining in third instar wing discs. Examples for Fz1–1-1V559E (V to E substitution) are shown in (B) (localization) and (F) (function). All other mutants analyzed as shown in (A) are listed in <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020158#pbio-0020158-t001" target="_blank">Table 1</a>. (C–E, G, and H) show the effects of the Fz2 C-tail-specific sequences. The Fz2 C-tail was truncated at the position of the Fz1 stop codon (amino acid L633), yielding a short Fz2 C-tail (2S). The localization (C and D) and GOF PCP function (G and H) of the respective chimeras, Fz1–2-2S and Fz1–1-2S, is shown. Note that both chimeras localize apically (C and D), and Fz1–1-2S shows a strong PCP GOF phenotype (H), very similar to Fz1–1-1 (see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020158#pbio-0020158-g003" target="_blank">Figure 3</a>B). Fz1–2-2S shows only a very weak PCP phenotype (G), mainly occurring at an anterior distal region of the wing (marked by arrow; the rest of the wing is wild-type). (E) Subcellular localization of Fz1–1-1C2. Fz1–1-1C2 is Fz1 with the addition of the Fz2-specific tail extension (see <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020158#s4" target="_blank">Materials and Methods</a>). Note ubiquitous protein localization within the apical–basal axis (E) and a much reduced PCP activity, as compared to wild-type Fz1–1-1, in the functional assay (I). The phenotype is much weaker than in wild-type Fz1 (compare with [F] and [H] and <a href="http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0020158#pbio-0020158-g003" target="_blank">Figure 3</a>B).