Overview

Laboratory of Proteomics and Protein Modifications

Post-translational modifications (PTMs) represent a major vehicle to diversify a cellular proteome, the inventory of all protein species in an organism. PTMs have critical roles in all the major cellular pathways and diseases. A protein can be potentially modified by more than 200 types of post-translational modifications, which are catalyzed by enzymes encoded by more than 5% of the genome in higher eukaryotes. A combination of a dozen PTM sites in a substrate protein could lead to more than a million possible protein structures with potentially different functions. Given the high abundance and diversities of PTMs, they are likely the most complex regulatory mechanisms in cells. Despite their critical roles in cells, little is known about their biology, except several most extensively studied PTMs. Functional characterizations of PTMs at the molecular level have been slow, largely due to a lack of suitable information infrastructure and technology infrastructure.

Our research aims to develop mass spectrometry-based proteomics technologies, and to use them to dissect PTM pathways. We are developing new mass spectrometry and bioinformatics tools for reliable, sensitive, and comprehensive analysis of proteins and PTMs. We are interested in dynamics analysis of diverse PTMs in order to understand their functions. We are using proteomics approach to characterize lysine acetylation, lysine propionylation, and lysine butyrylation pathways, the last two of which were recently discovered by us. We have begun applying a new bioinformatics tool, PTMap, also recently developed by us, to investigate PTM cross-talks. We also use powerful proteomics technologies in conjunction with biochemistry, molecular biology, and cell biology to decode PTM networks that have major implications for human health and are not amenable to conventional techniques.