Fig. 5.
Rescue experiments identify structural elements required for Mask's action in regulating MT stability. (A) A schematic of wild-type and mutant UAS-Mask transgenes used in the rescue experiments, and western blots (representative of three experiments) showing muscle expression of endogenous Mask in wild type or each of the four UAS-Mask transgenes expressed in muscles in mask null mutants. Note that the anti-Mask antibody does not recognize GFP-Mask-KH-Only protein, indicating that the antigen of this antibody lies outside of the Mask-KH-Only region. Anti-GFP western blots were performed to show the expression of GFP-Mask-KH-Only (indicated by an asterisk). All transgenes were expressed with expected sizes. The arrow indicates the expected size of the endogenous Mask protein. KD, kDa. (B) Confocal images (representative of three experiments) of MT in muscle 6 of wild type, mask null (mask10.22/Df), and rescues of mask null with MHC-Gal4-driven UAS-Mask, UAS-Mask-KH-Mut, UAS-Mask-KH-Only, or UAS-Mask-ANK transgenes. MTs were immunostained with an anti-acetylated-tubulin antibody. Scale bar: 10 µm. (C) Quantification of MT lengths. (D) Representative confocal images of muscle 4 NMJs in wild type, mask null (mask10.22/Df), rescues of mask null with pan-neuron (BG380-Gal4) driven wild type or mutant/deletion UAS-Mask transgenes as shown in A. Scale bar: 10 µm. (E) Quantification of the number of boutons, synaptic span and the number of branching points at the muscle 4 NMJs. Each data point was normalized to the size of the imaged muscle 4.