RT Journal Article
SR Electronic
T1 Enzymes degraded under high light maintain proteostasis by transcriptional regulation in Arabidopsis
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.10.03.462903
DO 10.1101/2021.10.03.462903
A1 Lei Li
A1 Owen Duncan
A1 Diep R Ganguly
A1 Chun Pong Lee
A1 Peter A. Crisp
A1 Akila Wijerathna-Yapa
A1 Karzan Salih
A1 Josua Trösch
A1 Barry J Pogson
A1 A. Harvey Millar
YR 2021
UL http://biorxiv.org/content/early/2021/10/03/2021.10.03.462903.abstract
AB Photo-inhibitory high light stress in Arabidopsis leads to increases in markers of protein degradation and transcriptional upregulation of proteases and proteolytic machinery, but proteostasis is largely maintained. We find significant increases in the in vivo degradation rate for specific molecular chaperones, nitrate reductase, glyceraldehyde-3 phosphate dehydrogenase, and phosphoglycerate kinase and other plastid, mitochondrial, peroxisomal, and cytosolic enzymes involved in redox shuttles. Coupled analysis of protein degradation rates, mRNA levels, and protein abundance reveal that 57% of the nuclear-encoded enzymes with higher degradation rates also had high light-induced transcriptional responses to maintain proteostasis. In contrast, plastid-encoded proteins with enhanced degradation rates showed decreased transcript abundances and must maintain protein abundance by other processes. This analysis reveals a light-induced transcriptional program for nuclear-encoded genes, beyond the regulation of PSII D1 subunit and the function of PSII, to replace key protein degradation targets in plants and ensure proteostasis under high light stress.Competing Interest StatementThe authors have declared no competing interest.