This video describes the time-resolved Förster resonance energy transfer or TR-FRET assay to determine endogenous protein phosphorylation with the help of donor and acceptor fluorophores tagged on antibodies specific to a test protein. This technique is designed to measure the phosphorylation of test proteins in cell lysates.
Protocol
1. Cell culture Maintain cells in a humidified 37 °C/5% CO2 incubator and culture with either DMEM supplemented with 10% fetal bovine serum (FBS) (HeLa and A431 cells) or RPMI supplemented with 15% FBS (U266B1 cells). Culture the cells until they reach 70-80% confluence, then trypsinize them and passage or use them for the assays. NOTE: Culture media contained phenol red. No serum starvation was conducted for any cell line prior to conducting the assays. …
Time-Resolved Forster Resonance Energy Transfer for Monitoring Protein Phosphorylation in Cells. J. Vis. Exp. (Pending Publication), e21329, doi: (2023).