The G595D substitution attenuates the affinity of Numb to clathrin/AP2.
A, domain structure of Numb. B, the protein levels of Numb (WT or G595D) expressed in CRL1601 cells after cycloheximide (CHX) treatment for the indicated times. C, the interaction of Numb variants (WT, G595D, and DLA) with α-adaptin and CHC analyzed by co-immunoprecipitation. D, immunofluorescent staining of Numbs (α-Myc) and clathrin-coated structures (α-adaptin) in CRL1601 cells. The Numb colocalized with α-adaptin was measured by ImageJ (Manders's overlap coefficient). Values are mean ± S.D., n = 20. **, p < 0.01. Scale bars, 10 μm. IP, immunoprecipitation; IB, immunoblot.