P100 aggregated data - CRISPR perturbations

The P100 assay is a mass spectrometry-based targeted proteomics assay that detects and quantifies a representative set of ~100 phosphopeptide probes that are present in a wide range of cell types and have been demonstrated to be modulated via perturbations. Briefly, phosphopeptides are enriched via an automated protocol from proteins derived from cell pellets that have been perturbed by various reagents. These peptides are mixed with a set of isotopically labeled internal standards that correspond to the analytes in the P100 assay. This mixture is introduced into a mass spectrometer using ultra-high pressure liquid chromatography (LCMS) and subjected to an analysis method specific for quantification of the P100 analytes. The behavior of more than 1000 unique phosphosites may be imputed from the profiles of the P100 analytes. The resulting profiles are suitable for molecular signature generation, querying of signatures across cell perturbations and types, and modeling of response networks in cellular systems.