Assay to probe proteolytic processing of Notch by γ-secretase.

With the increasing appreciation of the role of Notch in development and disease, measuring its cleavage and signaling activity in cellular systems has become important. Here we describe a cell-based method to analyze the cleavage of Notch at the S3 site by γ-secretase. HEK cells are transfected with an N-terminal truncated and myc-labeled mNotchΔE construct which can be easily and quantitatively detected by western blotting.