Small Heat Shock Proteins (sHsps) and Their Role in Human Disease

Molecular chaperones are proteins that assist in the unfolding or refolding of other macromolecular structures. Small heat shock proteins (sHsps) are key chaperones that are found across many species and play a large role in stress tolerance by preventing the irreversible aggregation of proteins that have become misfolded. When the protein quality control network is either overwhelmed with damaged proteins or is somehow defective, it often leads to various disease states. Understanding the mechanism of sHsps and the interactions with other chaperones has wide ranging implications, including fully recognizing the roles these proteins actually play in cellular stress, as well as in disease processes. The goal of this project is to analyze the phenotypes of Arabidopsis thaliana plants carrying mutations in genes that code for specific sHsps. The first mutant will have both class II sHsps, Hsp17.6 and Hsp17.7, knocked out. Both genes will be knocked out via the CRISPR/Cas9 mechanism, or by starting with a T-DNA knockout of Hsp17.6 combined with a CRISPR/Cas9 mutation of Hsp17.7. The other mutant will eliminate the organelle-targeted sHsps for both the mitochondria and chloroplasts, identified as 26.5_MT, 25.3_CP, 23.5_C/MT and 23.6_C/MT. These mutants will be created by crossing plants carrying single or double gene knockouts already available in the lab in order to create plants that are triple knockouts for all chloroplast and all mitochondrion-targeted sHsps. Understanding how these mutants behave and handle different stresses will provide a key understanding into how important sHsps are in these plants and in life.