Validation of a cell-based screen for insulin receptor modulators by quantification of insulin receptor phosphorylation.

Stimulation of a cell with insulin initiates a signal transduction cascade that results in cellular activities that include phosphorylation of the receptor itself. Measurement of the degree of phosphorylation can serve as a marker for receptor activation. Receptor phosphorylation has been measured using Western blot analysis, which is very low throughput and not easily quantifiable. The goal of this project was to develop a cell-based assay to measure receptor phosphorylation in high throughput. This report describes a cell-based assay for insulin receptor phosphorylation that is robust and amenable to high-volume screening in a microwell format.