Ca2+-dependent phosphoregulation of the plasma membrane Ca2+-ATPase ACA8 modulates stimulus-induced calcium signatures

Costa A., Luoni L., Marrano C., Hashimoto K., Köster P., Giacometti S., De Michelis M., Kudla J., Bonza M.

Research article (journal) | Peer reviewed

Abstract

Ca2+ signals are transient, hence, upon a stimulus-induced increase in cytosolic Ca2+ concentration, cells have to reestablish resting Ca2+ levels. Ca2+ extrusion is operated by a wealth of transporters, such as Ca2+ pumps and Ca2+/H+ antiporters, which often require a rise in Ca2+ concentration to be activated. Here, we report a regulatory fine-tuning mechanism of the Arabidopsis thaliana plasma membrane-localized Ca2+-ATPase isoform ACA8 that is mediated by calcineurin B-like protein (CBL) and CBL-interacting protein kinase (CIPK) complexes. We show that two CIPKs (CIPK9 and CIPK14) are able to interact with ACA8 in vivo and phosphorylate it in vitro. Transient co-overexpression of ACA8 with CIPK9 and the plasma membrane Ca2+ sensor CBL1 in tobacco leaf cells influences nuclear Ca2+ dynamics, specifically reducing the height of the second peak of the wound-induced Ca2+ transient. Stimulus-induced Ca2+ transients in mature leaves and seedlings of an aca8 T-DNA insertion line exhibit altered dynamics when compared with the wild type. Altogether our results identify ACA8 as a prominent in vivo regulator of cellular Ca2+ dynamics and reveal the existence of a Ca2+-dependent CBL-CIPK-mediated regulatory feedback mechanism, which crucially functions in the termination of Ca2+ signals.

Details about the publication

JournalJournal of Experimental Botany
Volume68
Issue12
Page range3215-3230
StatusPublished
Release year2017
Language in which the publication is writtenEnglish
DOI10.1093/jxb/erx162
Link to the full texthttps://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85029215784&origin=inward
KeywordsArabidopsis thaliana; Ca2+ signature; Calcineurin B-like protein; CBL-interacting protein kinases; Phosphorylation; Plasma membrane Ca2+-ATPase

Authors from the University of Münster

Köster, Philipp
Molecular Genetics and Cell Biology of Plants - Group Prof. Jörg Kudla
Kudla, Jörg
Molecular Genetics and Cell Biology of Plants - Group Prof. Jörg Kudla