title: A calcium sensor - protein kinase signaling module diversified in plants and is retained in all lineages of Bikonta species.
abstract: Calcium (Ca(2+)) signaling is a universal mechanism of signal transduction and involves Ca(2+) signal formation and decoding of information by Ca(2+) binding proteins. Calcineurin B-like proteins (CBLs), which upon Ca(2+) binding activate CBL-interacting protein kinases (CIPKs) regulate a multitude of physiological processes in plants. Here, we combine phylogenomics and functional analyses to investigate the occurrence and structural conservation of CBL and CIPK proteins in 26 species representing all major clades of eukaryotes. We demonstrate the presence of at least singular CBL-CIPK pairs in representatives of Archaeplastida, Chromalveolates and Excavates and their general absence in Opisthokonta and Amoebozoa. This denotes CBL-CIPK complexes as evolutionary ancient Ca(2+) signaling modules that likely evolved in the ancestor of all Bikonta. Furthermore, we functionally characterize the CBLs and CIPK from the parabasalid human pathogen Trichomonas vaginalis. Our results reveal strict evolutionary conservation of functionally important structural features, preservation of biochemical properties and a remarkable cross-kingdom protein-protein interaction potential between CBLs and CIPKs from Arabidopsis thaliana and T. vaginalis. Together our findings suggest an ancient evolutionary origin of a functional CBL-CIPK signaling module close to the root of eukaryotic evolution and provide insights into the initial evolution of signaling networks and Ca(2+) signaling specificity.
authors.affiliation: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, 48149 Münster, Germany.
authors.forename: Linda
authors.initials: L
authors.lastname: Beckmann
authors.affiliation: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, 48149 Münster, Germany.
authors.forename: Kai H
authors.initials: KH
authors.lastname: Edel
authors.affiliation: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, 48149 Münster, Germany.
authors.forename: Oliver
authors.initials: O
authors.lastname: Batistič
authors.affiliation: Institut für Biologie und Biotechnologie der Pflanzen, Universität Münster, Schlossplatz 7, 48149 Münster, Germany.|College of Science, King Saud University, Riyadh 11451, Kingdom of Saudi Arabia.
authors.forename: Jörg
authors.initials: J
authors.lastname: Kudla
mesh_terms: D019143:Evolution, Molecular; D010802:Phylogeny; D010940:Plant Proteins / Q000235:genetics*; D010944:Plants / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics; D014246:Trichomonas vaginalis / Q000235:genetics
chemical_list: D010940:Plant Proteins; D015800:Protozoan Proteins; D017346:Protein Serine-Threonine Kinases