Pseudomonas syringae pv. syringae Infection Orchestrates the Fate of the Arabidopsis J Domain Containing Cochaperone and Decapping Protein Factor 5

Abstract

Plants are equipped with numerous defense strategies to combat any biotic or abiotic challenges. Several protein factors are constantly engaged in the surveillance process, thus production of any aberrant messenger RNAs (mRNAs) and proteins are restricted. Eukaryotic mRNAs go through a number of scrutiny processes, whereby several protein components including mRNA decapping factors play a critical role in degrading the non-physiological mRNAs, which would otherwise have detrimental effect when translated. Similarly newly synthesized proteins also pass through quality control process mediated by chaperones and cochaperones harboured within the endoplasmic reticulum, ensuring proper protein folding and minimize the occurrence of protein misfolding. Interestingly, the results of the present study revealed that the decapping protein factor, DCP5 of the Arabidopsis thaliana physically interacts with the J domain-containing cochaperone, ERdj3B in the processing bodies (P-bodies). Upon pathogen infection by the Pseudomonas syringae pv. syringae B728a strain (PssB728a), the ERdj3B was induced for degradation via the 26S proteasome pathway as early as 120 min post infection (mpi). Also under pathogen-challenged conditions, DCP5 relocalizes to the cytoplasm and the number of DCP5-induced P-bodies was significantly reduced at 90 and 120 mpi. The findings of the present investigation highlight the possible significance of this interaction, primarily contributing for maintaining proteostasis and their plausible role during plant defense process.