Protein phosphorylation plays a critical role in liver development and function. Comprehensively cataloging the phosphoproteins and their phosphorylation sites in human liver tissue will facilitate the understanding of physiological and pathological mechanisms of liver.
Two approaches were performed to further improve the coverage of phosphoproteome analysis of human liver tissue. In one approach, ten-replicated long-gradient LC-MS/MS runs were performed to analyze the enriched phosphopeptides, which resulted in the localization of 1080 phosphorylation sites from 495 proteins. In another approach, proteins from liver tissue were first fractionated by SDS-PAGE and then long-gradient LC-MS/MS analysis was performed to analyze the phosphopeptides derived from each fraction, which resulted in the localization of 1786 phosphorylation sites from 911 proteins. Combining the results of the two approaches, identification of 2225 nonredundant phosphorylation sites from 1023 proteins was obtained.
Protein lysine acetylation has emerged as a key posttranslational modification in cellular regulation, in particular through the modification of histones and nuclear transcription regulators. We show that lysine acetylation is a prevalent modification in enzymes that catalyze intermediate metabolism.
dbLMP is an online systems biology resource providing comprehensive information and database for the study of protein post-translation modifications. In addition to providing an extensive, manually currated phosphorylation site database, lysine acetylation database is also privded.