Chemistry and Biology of Cys-based Redox Signaling
Our research is centered around chemical biology approaches to investigate Cys-based protein oxidations, which can be induced by the reactive oxygen species (ROS) in redox signaling. ROS are important signaling molecules regulating multiple biological processes in physiology and contributing to the etiology of diseases, including cancers, cardiovascular diseases, and neurodegeneration. As the reactive species, ROS causes protein cysteine oxidations (cys-PTM), such as protein glutathionylation, which serves as a fundamental molecular event behind redox-mediated physiology and diseases. Therefore, our group seeks to identify protein glutathionylation via chemical proteomics and understand its functional events in biological models, while pursuing pharmacological approaches to regulate redox biology (see more for models). We use interdisciplinary approaches, primarily based on chemical biology, along with protein biochemistry, cell biology, and medicinal chemistry.
1. Protein Glutathionylation in Physiology and Diseases
Our current research focused on the investigation of protein glutathionylation. Glutathionylation is the disulfide bond formation of a protein cysteine residue with intracellular glutathione that forms in response to ROS and oxidative stress. We develop chemical tools and methods to investigate protein glutathionylation in oxidative stress associated with cancer and cardiovascular diseases.
Chemical Approach to Investigate Protein Glutathionylation
We have previously developed an approach, called clickable glutathione, that labels glutathione with a clickable group to identify and characterize protein glutathionylation. The clickable group provides a chemical tag that allows for sensitive, selective, and versatile detection of glutathionylation. We are applying our approach for the identification of protein glutathionylation, especially in new cellular and mouse models, via mass spectrometry with LC-MS/MS.
Chemical Proteomics and Bioinformatics for Identification of Protein Glutathionylation
Mass spectrometry-based cysteine profiling is now well-established in identifying functional cysteines in the proteome. We use a chemoproteomic strategy with clickable glutathione to identify and quantify glutathionylation on specific cysteine sites. We analyze proteomic data with MS analysis, bioinformatic analysis, and structural analysis. Bioinformatic analyses identify proteins of biological significance associated with diseases or specific biological processes. Structural analyses provide a molecular hypothesis that proposes functional outcomes upon glutathionylation. Overall, chemoproteomics, bioinformatics, and structural analysis are combined to identify and pinpoint potential biologically or functionally important cysteines susceptible to glutathionylation.
Biological Models for Protein Glutathionylation
Glutathionylation in Cardiomyocytes: Reactive oxygen species (ROS) are significant factors contributing to heart and muscle diseases. We apply our strategy to understand glutathionylation in cardiomyocytes. This project aims to interrogate an interplay between ROS, glutathionylation, and sarcomere dysfunction. In this project, our major goal is to identify important cardiac or sarcomeric proteins susceptible to glutathionylation and characterize functional outcomes of glutathionylation on sarcomeric proteins
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Glutathionylation in Cell Migration: Cell migration is a fundamental process in the development and maintenance of organisms, such as embryonic development, wound healing, and inflammation. Deregulated cell migration plays a crucial role in many diseases, including chronic wounds and cancer metastasis. Hydrogen peroxide or ROS are a crucial driver of cell migration via induction of protein cysteine oxidations. In this project, our major goal is to identify cysteines susceptible to glutathionylation during cell migration and analyze their regulatory roles in cell migration.
2. Biochemistry of Enzymes in Redox Regulation
Redox homeostasis is maintained by a balance of oxidases and redox enzymes that produce and remove the reactive species, respectively. Therefore, altered expression and/or activities of oxidases and redox enzymes directly contributed to dysregulated redox states associated with various pathophysiology. We seek to understand the biochemistry of oxidases in terms of their structure, biological function, and regulation with the ultimate goal of developing pharmacological strategies.
3. Glutathione Derivatives as Chemical Tools in Medicine
Glutathione is a tripeptide, the major abundant thiol, typically known for its canonical role in buffering the redox state and maintaining redox homeostasis. However, the emerging examples support its non-canonical roles, beyond the redox function, in regulating specific proteins with therapeutic potential. We seek to develop glutathione derivatives as chemical tools for understanding the non-canonical roles of glutathione while pursuing therapeutic direction.
