Kinase activity and calmodulin binding are essential for growth signaling by the phytosulfokine receptor PSKR1

Hartmann J, Fischer C, Dietrich P, Sauter M (2014)

Publication Language: English

Publication Status: Published

Publication Type: Journal article, Original article

Publication year: 2014

Journal

Plant Journal Wiley

Publisher: Blackwell Publishing Ltd

Book Volume: 78

Pages Range: 192-202

Journal Issue: 2

DOI: 10.1111/tpj.12460

Open Access Link: http://onlinelibrary.wiley.com/doi/10.1111/tpj.12460/abstract;jsessionid=0E312766978E24FABE86144FEE778850.f02t02?systemMessage=Wiley+Online+Library+will+be+unavailable+on+Saturday+25th+March+from+07%3A00+GMT+%2F+03%3A00+EDT+%2F+15%3A00+SGT+for+4+hour

Abstract

The cell growth-promoting peptide phytosulfokine (PSK) is perceived by leucine-rich repeat (LRR) receptor kinases. To elucidate PSK receptor function we analyzed PSKR1 kinase activity and binding to Ca sensors and evaluated the contribution of these activities to growth control in planta. Ectopically expressed PSKR1 was capable of auto- and transphosphorylation. Replacement of a conserved lysine within the ATP-binding region by a glutamate resulted in the inhibition of auto- and transphosphorylation kinase activities. Expression of the kinase-inactive PSKR1(K762E) receptor in the pskr null background did not restore root or shoot growth. Instead, the mutant phenotype was enhanced suggesting that the inactive receptor protein exerts growth-inhibitory activity. Bioinformatic analysis predicted a putative calmodulin (CaM)-binding site within PSKR1 kinase subdomain VIa. Bimolecular fluorescence complementation analysis demonstrated that PSKR1 binds to all isoforms of CaM, more weakly to the CaM-like protein CML8 but apparently not to CML9. Mutation of a conserved tryptophan (W831S) within the predicted CaM-binding site strongly reduced CaM binding. Expression of PSKR1(W831S) in the pskr null background resulted in growth inhibition that was similar to that of the kinase-inactive receptor. We conclude that PSK signaling requires Ca /CaM binding and kinase activity of PSKR1 in planta. We further propose that the inactivated kinase interferes with other growth-promoting signaling pathway(s). © 2014 The Authors The Plant Journal © 2014 John Wiley & Sons Ltd.

Authors with CRIS profile

Cornelia Fischer Professur für Zellbiologie der Pflanzen Petra Dietrich Professur für Zellbiologie der Pflanzen

Involved external institutions

Christian-Albrechts-Universität zu Kiel DE Germany (DE)

How to cite

APA:

Hartmann, J., Fischer, C., Dietrich, P., & Sauter, M. (2014). Kinase activity and calmodulin binding are essential for growth signaling by the phytosulfokine receptor PSKR1. Plant Journal, 78(2), 192-202. https://dx.doi.org/10.1111/tpj.12460

MLA:

Hartmann, Jens, et al. "Kinase activity and calmodulin binding are essential for growth signaling by the phytosulfokine receptor PSKR1." Plant Journal 78.2 (2014): 192-202.

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