6533b7d4fe1ef96bd1262e93

RESEARCH PRODUCT

Study of the role of the CDC48 chaperone protein in plant immunity

subject

description

The chaperone protein CDC48 (Cell division cycle 48) is a major regulator of the quality control of proteins and is involved in various cellular processes in animals and yeast. In contrast, the role of CDC48 in plants is poorly known. In the present work, we investigated the function of CDC48 in plant immunity thanks to the cryptogein/tobacco biological model, cryptogein being produced by the oomycete phytophthora cryptogea.Three strategies were carried out. First, the dynamic of accumulation CDC48 together with intracellular events inherent to the immune response were analyzed in both wild-type and CDC48 overexpressing tobacco cells (CDC48-TAP line). Second, a list if CDC48 partners was established based on immunoprecipitation assays followed by mass spectroscopy analysis. Among those partners the cytosolic form of acorbate peroxidase (cAPX), a central enzyme of the regulation of the redox status regulation, has been specifically studied. Finally, a computational analysis of the partner list of CDC48 and the subsequent generation of the protein-protein interaction (PPI) network of CDC48 in Arabidopsis thaliana were undertook.Our data indicated that the activation of the immune response is accompanied by an induction of the accumulation of both CDC48 transcript and protein. In addition, an early and exacerbated cell death was observed in the CDC48-TAP line, suggesting a role for CDC48 in the hypersensitive response. The interaction between CDC48 and cAPX was confirmed by different approaches. Interestingly, the activity of CDC48 and its dynamic of accumulation were strongly impacted in the CDC48 overexpressing line. Accordingly, a dysregulation of the redox status also occurred in this line. Finally, the computational analysis of the CDC48 PPI network highlighted new potential target proteins including proteins involved in the metabolism of S-adenosylmethionine, a substrate molecule of trans-methylation reactions and precursor of ethylene and nicotianamine.To summarize, this work provides new information about CDC48 in plant biology. It indicates that CDC48 is mobilized by plant cells undergoing an immune response and impacts the redox status through the regulation of the cAPX turnover. New research avenues emerged from our study, notably a putative role of CDC48 in the regulation of S-adenosylmethionine biosynthesis and in the establishment of hypersensitive response through process which remain to be investigated