title: PA, a stress-induced short cut to switch-on ethylene signalling by switching-off CTR1?
abstract: Constitutive triple response 1 (CTR1) is a protein kinase that represses plant responses to ethylene. Recently, we have shown that CTR1 function is negatively regulated by the lipid second messenger phosphatidic acid (PA) in vitro.1 PA was shown to inhibit (1) CTR1's protein kinase activity, (2) the intramolecular interaction between N-terminus and kinase domain, and (3) the interaction of CTR1 with the ethylene receptor ETR1. PA typically accumulates within minutes in response to biotic or abiotic stresses, which are known to induce ethylene formation. Although long-term treatment with ethephon does stimulate PA accumulation, our results show no fast increase in PA in response to ethylene. A speculative model is presented which explains how stress-induced PA formation could switch on downstream ethylene responses via interaction of the lipid with CTR1.
authors.affiliation: Section of Plant Physiology; Swammerdam Institute for Life Sciences; University of Amsterdam; Amsterdam, the Netherlands.
authors.forename: Christa
authors.initials: C
authors.lastname: Testerink
authors.forename: Paul B
authors.initials: PB
authors.lastname: Larsen
authors.forename: Fionn
authors.initials: F
authors.lastname: McLoughlin
authors.forename: Dieuwertje
authors.initials: D
authors.lastname: van der Does
authors.forename: John Aj
authors.initials: JA
authors.lastname: van Himbergen
authors.forename: Teun
authors.initials: T
authors.lastname: Munnik
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