Molecular Mechanisms Associated with Protein Misfolding in Plants

Random mutations are generally thought to have deleterious effects on protein folding and function. Although proteins are marginally stable and exhibit a level of mutational robustness, they do misfold under excessive environmental stresses or mutations. In human, continual aggregation of certain misfolded proteins could lead to pathology, including many neurodegenerative diseases such as Alzheimer’s, Huntington, Parkinson’s, and the prion maladies. Plants contain rapidly evolving specialized metabolic system, and presumably encounter destabilized evolutionary intermediates along their mutational trajectories. Have plants evolved unique molecular mechanisms that assist folding of those destabilized proteins and/or mitigate proteotoxicity arising from protein misfolding? We use the model plant Arabidopsis thaliana to examine the in vivo function and behavior of mutant enzymes that exhibit broadened product promiscuity and/or decreased folding stability in vitro. We attempt to identify genetic components involved in cellular mechanisms that assist folding or alter product profile of these mutant enzymes.