Updated project metadata. HeLa cells were fracitonated into nuclear soluble, chromatin bound and cytosolic. Extracts were immunoprecipitated with a CSN3 antibody, then eluted with glycine. Proteins were digested, then enriched for phosphopeptides. Samples were analyzed on an LTQ-Orbitrap. Data was analyzed using the TRansOMics software for time alignment and feature detection. MS/MS spectra searched using Mascot.