Biochemical regulation of in vivo function of plant calcium-dependent protein kinases (CDPK)

AbstractCalcium (Ca2+) is a major second messenger in plant signal transduction mediating stress- and developmental processes. Plant Ca2+-dependent protein kinases (CDPKs) are mono-molecular Ca2+-sensor/protein kinase effector proteins, which perceive Ca2+ signals and translate them into protein phosphorylation and thus represent an ideal tool for signal transduction. This review focuses on recent developments in CDPK structural analysis and CDPK in vivo phosphorylation substrate identification. We discuss mechanisms implicated in the in vivo regulation of CDPK activity including Ca2+ binding to the CDPK EF-hands, Ca2+-triggered intra-molecular conformation changes, and CDPK (auto)-phosphorylation. Moreover, we address regulation and integration into signaling cascades of selected members of the plant CDPK family, for which in vivo function and phosphorylation in abiotic and biotic stress signaling have been demonstrated. This article is part of a Special Issue entitled: 12th European Symposium on Calcium