A chaperone network that includes HSP70 and HSP90 is essential for maintaining proteins in their functional conformation and preventing their aggregation. Plants also harbour various co-chaperones, such as J-proteins, which stimulate HSP70 activity, but the localisation and functions of many of these factors is unclear. Now, Serena Schwenkert and colleagues (Dittmer et al., 2021) characterise DJC31 and DJC62, two J-proteins that carry clamp-type tetratricopeptide repeat domains, in Arabidopsis thaliana. Using GFP fusion constructs as well as cell fractionation, they determine that DJC31 and DJC62 localise to the cytosolic side of the ER membrane, and not to chloroplasts as previously suggested. The two proteins interact with HSP70 and HSP90 as shown by bimolecular fluorescence complementation and the authors also demonstrate that the interaction with HSP70 is essential; constructs in which the domain required to activate HSP70 is mutated fail to complement the growth retardation and curled leaf mutant phenotype of djc31 djc62 double mutants. Finally, the authors assess the function of DJC31 and DJC62 in abiotic stress responses and find that double mutants are more sensitive to osmotic stress but, surprisingly, more tolerant towards drought stress compared to wild-type plants. Double mutants were also hypersensitive to abscisic acid (ABA). Taken together, this study identifies DJC31 and DJC62 as novel plant co-chaperones that are important for osmotic and drought stress responses, likely through ABA-mediated signalling.
New co-chaperones in plant stress responses
New co-chaperones in plant stress responses. J Cell Sci 1 October 2021; 134 (19): e134_e1903. doi:
Download citation file:
Advertisement
Cited by
Imaging Cell Architecture and Dynamics
We are still welcoming submissions for our upcoming Special Issue: Imaging Cell Architecture and Dynamics. This issue will be coordinated by two Guest Editors: Lucy Collinson (The Francis Crick Institute, UK) and Guillaume Jacquemet (University of Turku, Finland). Extended submission deadline: 29 March 2024.
Journal of Cell Science - more than just a journal
People who know JCS well will know that we're more than just a journal and that our community – the cell biology community – really is at the heart of everything we do. Read the full Editorial by Editor-in-Chief Michael Way and Executive Editor Seema Grewal.
2024 Journal Meeting 'Diversity and Evolution in Cell Biology'
Registration is open for our 2024 Journal Meeting Diversity and Evolution in Cell Biology, which aims to bring together evolutionary biologists and cell biologists investigating diverse aspects of cellular physiology. Submit your abstract by 5 April. Final registration deadline: 3 May 2024.
Workshop: Roles of Lipids in Nuclear Homeostasis and Genome Stability
Early-career researchers interested in the roles of nuclear lipids, apply now for one of the ten funded places at this Workshop, which will take place 14-17 October 2024. Application deadline: 19 April.
Reasons to submit to Journal of Cell Science
There are many benefits to publishing in Journal of Cell Science - read more about why you should choose JCS or visit our submission page now.