Kataria, P. | bioRxiv Science

bioRxiv2024

Control of heat and oxidative stress adaptation by the DJ-1 paralogs in Arabidopsis thaliana

Plant growth and development are highly regulated processes and are majorly controlled by various environmental factors, whose extreme exposures lead to chronic stress conditions promoting reactive oxygen species (ROS) and carbonyl species (RCS) production. ROS and RCS extensively damage cellular biomolecules and organelles, affecting plants viability and development. Emerging reports highlight that the multi-stress responding DJ-1 superfamily proteins are critical in attenuating cytotoxic effects associated with abiotic stress. The current report, validated in yeast and plant models, shows that AtDJ-1C and AtDJ-1E are robust antioxidants that scavenge ROS and improve survival under oxidative stress. Although they lack conventional glyoxalases and do not attenuate the glycation of proteins, AtDJ-1C and AtDJ-1E preserve the GSH pool and regulate redox homeostasis. Moreover, transcriptome profiling indicates that levels of AtDJ-1C and AtDJ-1E are rapidly established to counter heat and oxidative stress conditions. Notably, the knockdown of AtDJ-1C and AtDJ-1E promotes detrimental alterations such as reduced chlorophyll retention, impaired root morphogenesis, and induced sensitivity to heat stress due to ROS elevation. Contrastingly, overexpression of AtDJ-1C and AtDJ-1E improved plant height and rosette formation under physiological conditions. In conclusion, our study unravels the pivotal functions of Arabidopsis thaliana DJ-1C and DJ-1E in governing plant health and survival under heat and oxidative stress conditions.

plant biology↗

bioRxiv2022

Saccharomyces cerevisiae DJ-1 paralogs maintain genome integrity through glycation repair of nucleic acids and proteins

Reactive carbonyl species (RCS) such as methylglyoxal and glyoxal are potent glycolytic intermediates that extensively damage cellular biomolecules leading to genetic aberration and protein misfolding. Hence, RCS levels are crucial indicators in the progression of various pathological diseases. Besides the glyoxalase system, emerging studies report highly conserved DJ-1/ThiJ/PfpI superfamily proteins as critical regulators of RCS. DJ-1 superfamily proteins, including the human DJ-1, a genetic determinant of Parkinsons disease possess diverse physiological functions paramount for combating multiple stressors. Although S. cerevisiae retains four DJ-1 orthologs (namely Hsp31, Hsp32, Hsp33, and Hsp34), their physiological relevance and collective requirement are still obscure due to their close sequence similarity. Here, we report for the first time that the yeast DJ-1 orthologs function as novel enzymes involved in the preferential scavenge of glyoxal and methylglyoxal, toxic metabolites, and genotoxic agents. At the cellular level, their collective loss induces chronic glycation of the proteome, and nucleic acids, resulting in a spectrum of genetic mutations and reduced mRNA translational efficiency. Furthermore, the Hsp31 paralogs efficiently repair severely glycated macromolecules derived from carbonyl modifications. They also participate in genome maintenance as their absence upregulates DNA damage response pathways when exposed to different genotoxins. Interestingly, yeast DJ-1 orthologs provide robust organellar protection by redistributing into mitochondria to alleviate the glycation damage of mitochondrial DNA and proteins. Taken together, our study uncovers the existence of a novel glycation repair pathway in S. cerevisiae and a possible neuroprotective mechanism of how hDJ-1 confers mitochondrial health during carbonyl stress.

biochemistry↗