Large-scale phosphorylation analysis of mouse liver

Protein phosphorylation is a complex network of signaling and regulatory events that affects virtually every cellular process. Our understanding of the nature of this network as a whole remains limited, largely because of an array of technical challenges in the isolation and high-throughput sequencing of phosphorylated species. In the present work, we demonstrate that a combination of tandem phosphopeptide enrichment methods, high performance MS, and optimized database search/data filtering strategies is a powerful tool for surveying the phosphoproteome. Using our integrated analytical platform, we report the identification of 5,635 nonredundant phosphorylation sites from 2,328 proteins from mouse liver. From…