TY - JOUR
T1 - Subfamily C7 Raf-like kinases MRK1, RAF26, and RAF39 regulate immune homeostasis and stomatal opening in Arabidopsis thaliana
AU - Gonçalves Dias, Márcia
AU - Doss, Bassem
AU - Rawat, Anamika
AU - Siegel, Kristen R.
AU - Mahathanthrige, Tharika
AU - Sklenar, Jan
AU - Rodriguez Gallo, Maria Camila
AU - Derbyshire, Paul
AU - Dharmasena, Thakshila
AU - Cameron, Emma
AU - Uhrig, R. Glen
AU - Zipfel, Cyril
AU - Menke, Frank L. H.
AU - Monaghan, Jacqueline
N1 - Data availability statement: Any novel germplasm or clones described in this article will be made freely available upon request. The person responsible for sharing materials is the author of correspondence [email protected]. Proteomics data has been deposited to the ProteomeXchange Consortium via the PRIDE (Perez-Riverol et al., 2019; https://www.ebi.ac.uk/pride/) partner repository with the dataset identifiers PXD052803 and PXD055293.
Funding Information: Biotechnology and Biological Sciences Research Council; Ontario Ministry of Research and Innovation. Grant Number: ER21-16-100; Natural Sciences and Engineering Research Council of Canada. Grant Numbers: RGPAS-492902-2016, RGPIN-2016-04787.
PY - 2024/12
Y1 - 2024/12
N2 - The calcium-dependent protein kinase CPK28 regulates several stress pathways in multiple plant species. Here, we aimed to discover CPK28-associated proteins in Arabidopsis thaliana. We used affinity-based proteomics and identified several potential CPK28 binding partners, including the C7 Raf-like kinases MRK1, RAF26, and RAF39. We used biochemistry, genetics, and physiological assays to gain insight into their function. We define redundant roles for these kinases in stomatal opening, immune-triggered reactive oxygen species (ROS) production, and resistance to a bacterial pathogen. We report that CPK28 associates with and trans-phosphorylates RAF26 and RAF39, and that MRK1, RAF26, and RAF39 are active kinases that localize to endomembranes. Although Raf-like kinases share some features with mitogen-activated protein kinase kinase kinases (MKKKs), we found that MRK1, RAF26, and RAF39 are unable to trans-phosphorylate any of the 10 Arabidopsis mitogen-activated protein kinase kinases (MKKs). Overall, our study suggests that C7 Raf-like kinases associate with and are phosphorylated by CPK28, function redundantly in stomatal opening and immunity, and possess substrate specificities distinct from canonical MKKKs.
AB - The calcium-dependent protein kinase CPK28 regulates several stress pathways in multiple plant species. Here, we aimed to discover CPK28-associated proteins in Arabidopsis thaliana. We used affinity-based proteomics and identified several potential CPK28 binding partners, including the C7 Raf-like kinases MRK1, RAF26, and RAF39. We used biochemistry, genetics, and physiological assays to gain insight into their function. We define redundant roles for these kinases in stomatal opening, immune-triggered reactive oxygen species (ROS) production, and resistance to a bacterial pathogen. We report that CPK28 associates with and trans-phosphorylates RAF26 and RAF39, and that MRK1, RAF26, and RAF39 are active kinases that localize to endomembranes. Although Raf-like kinases share some features with mitogen-activated protein kinase kinase kinases (MKKKs), we found that MRK1, RAF26, and RAF39 are unable to trans-phosphorylate any of the 10 Arabidopsis mitogen-activated protein kinase kinases (MKKs). Overall, our study suggests that C7 Raf-like kinases associate with and are phosphorylated by CPK28, function redundantly in stomatal opening and immunity, and possess substrate specificities distinct from canonical MKKKs.
KW - Arabidopsis thaliana
KW - C7 Raf-like kinase
KW - CPK28
KW - immunity
KW - MRK1
KW - RAF26
KW - RAF39
KW - stomata
UR - http://www.scopus.com/inward/record.url?scp=85207550802&partnerID=8YFLogxK
U2 - 10.1111/nph.20198
DO - 10.1111/nph.20198
M3 - Article
C2 - 39449177
AN - SCOPUS:85207550802
SN - 0028-646X
VL - 244
SP - 2278
EP - 2294
JO - New Phytologist
JF - New Phytologist
IS - 6
ER -