Figure 10. Membrane tethered activated Arm induces relocalization of Notch in epithelial cells.

Analysis of the distribution and localization of Notch, monitored with a NICD antibody (in red), and endogenous Arm (in green) in wing discs expressing a myristylated N-terminal deleted Armadillo, Arm^ΔNMyr (A), or the same mutant without the myristylated signal, Arm^ΔN (B), under the control of dpp-Gal4. Confocal sections of the wing pouch are shown at the level of the adherens junctions (A and B) and a more basolateral (A₁ and B₁) region. The expression of Arm^ΔNMyr promotes an obvious accumulation of endogenous Notch in the apical (A) and basolateral (A₁) membranes of the cells. The effect is very mild, though still visible, in the case of Arm^ΔN. Both forms of Arm also cause an effect in the endogenous Arm: it is weakly displaced from the apical membrane and accumulates in the cells, more obvious in Arm^ΔN (B₁, for details of the distribution, effects, and interactions of these mutants with endogenous Armadillo, see [70]). Scale bar, 20 µm.