Fig. 2.
Dlg regulates cortical Scrib stability. FRAP assay (A) shows distinct mobility of Scrib, Dlg, and Lgl in WT cells; Scrib is most stable and Lgl is most dynamic. (B) Scrib shows an approximately fourfold increase in recovery kinetics in dlg RNAi cells. (C) Schematic of the mutant dlg alleles and scrib alleles used in D–M. dlgm30 harbors a point mutation in the SH3 domain (L632P, asterisk). dlgv59 contains a deletion resulting in frameshift and truncation of the GUK domain. dlg1P20 is a nonsense mutation truncating the GUK domain. scrib4 truncates all four PDZ domains. Dotted lines indicate truncations. Compared to WT (D–F), aPKC (G), and Lgl (I) localizations are unaffected in cells mutant for a dlg GUK-deficient allele. Scrib localization (H) is partially affected, although this may be due to reduced stability of mutant Dlg. aPKC (J), Dlg (J′), and Lgl (K) localizations are unaffected in cells mutant for a scrib allele lacking PDZ domains. (L) aPKC mislocalizes laterally in cells mutant for a dlg SH3 point mutant allele. Scrib (L′) and Lgl (M) also exhibit cytoplasmic mislocalization in these cells. (Scale bars, 10 µm.) Error bars represent 95% confidence intervals. All follicles are stage 7, except K and M, which are stages 8 and 6, respectively.