My research interests involve understanding the mechanisms of cellular protein homeostasis and the protein quality control systems (PQC) under physiological and stress conditions. Plant Arabidopsis thaliana and yeast Saccharomyces cerevisiae are used as model organisms. Proteomics, molecular biology, biochemical and biophysical approaches are applied to study how molecular chaperones are involved in de novo protein synthesis and protein functions, and the interplay of chaperones and the proteasome in PQC upon protein misfolding.
Research Area: Biochemistry, Cell and Molecular Biology, Plant Biology
Role and mechanism of Arabidopsis organellar molecular chaperone HSP90s
The heat shock protein 90 (HSP90) is a molecular chaperone which aids in folding a variety of proteins (termed HSP90 substrates), many of which are protein kinases and transcription factors playing key roles in cellular signaling pathways. In plants, HSP90s are essential for proper organelle function, buffering genetic variations and for the plant innate immune responses. Our laboratory is interested in the role and mechanism of action of HSP90 in plant development, organelle functions and in plant adaptation to environmental changes with a focus on the organellar HSP90 isoforms. Genetic, biochemical and proteomics approaches are applied to explore and characterize the Arabidopsis thaliana organellar HSP90 interacting proteins, which are composed of putative substrates and cochaperones under both normal and stress conditions. This will facilitate the identification of particular cellular pathways in which HSP90 is involved.
Ubiquitin-independent protein degradation by the proteasome
The proteasome is a multiple-subunit protein complex, whose canonical function is to selectively degrade denatured or misfolded proteins in a ubiquitin and ATP-dependent manner. Improper proteasome function is thought to be one mechanism that underlies the development of neurodegenerative diseases. However, the structure and function of the proteasome regulatory particle, particularly its well recognized function in degrading ubiquitin independent protein substrates, is far from being clearly understood. We are interested in the mechanism of ubiquitin-independent protein degradation by the proteasome. Specifically, by using model substrates and using baking yeast as a model organism, we are interested in the ubiquitin-independent substrate recognition mechanism and the general role of ubiquitin-independent protein degradation in regulating cellular processes.