Figure 1.
Distinct Mechanisms of Notch Activation Have Opposing Temperature Dependencies
(A) Ligand-independent signaling induced by Dx is reduced by Su(dx) coexpression.
(B) ND505A prevents Dl-induced signaling.
(C and D) Coimmunoprecipitates: Dx binds ND505A (C) but not NR2027 (D).
(E) Opposite temperature dependence of basal and Dx-induced N signaling. Su(dx) expression increases basal N signal at low temperatures but decreases signal at high temperatures.
(F) Dl-induced signaling (fold change) increases with temperature. Su(dx) reduces signal more effectively at high temperatures.
(G) Signaling from extracellular truncated N constructs NEXT and NICD is unaffected by temperature.
(H) In situ for wingless expression in wing imaginal discs marks N signaling (discs shown dorsal up, ventral below). Dx expressed along anterior-posterior compartment boundary using ptc-Gal4. In WT discs, Dx-activated N signaling (arrow) becomes weaker at higher temperatures. In Su(dx) mutant discs, the temperature dependency of Dx activity is reversed.
Data in (A), (B), (E), (F) and (G) are displayed as means ± SEM, p < 0.05 (minimum of n = 3) for all comparisons stated in legend (Student t test). See also Figure S1.