Opposite changes in membrane fluidity mimic cold and heat stress activation of distinct plant MAP kinase pathways

• DOI: 10.1046/j.1365-313x.2002.01384.x
• Publication Date: 2003-03-12T22:07:41Z
• Authors: Veena Sangwan; Björn Lárus Örvar; John Beyerly; Heribert Hirt; Rajinder S. Dhindsa
• Keywords: 0301 basic medicine; Hot Temperature; MAP Kinase Signaling System; Membrane Fluidity; Acclimatization; 1060 Biologie; Cold Temperature; Enzyme Activation; 03 medical and health sciences; Calcium-Calmodulin-Dependent Protein Kinases; Calcium; 1060 Biology; Mitogen-Activated Protein Kinases; Cytoskeleton; Heat-Shock Response; Medicago sativa; Signal Transduction

Summary Mitogen‐activated protein kinases (MAPKs) appear to be ubiquitously involved in signal transduction during eukaryotic responses extracellular stimuli. In plants, no heat shock‐activated MAPK has so far been reported. Also, whereas cold activates specific plant MAPKs such as alfalfa SAMK, mechanisms of activation are unknown. Here, we report a (HAMK) immunologically related ERK (Extracellular signal‐Regulated Kinase) superfamily kinases. Molecular heat‐activation HAMK and cold‐activation SAMK were investigated. We show that requires membrane rigidification, occurs through fluidization. The temperature stress‐ structure‐dependent both is mimicked at 25°C by destabilizers microfilaments microtubules, latrunculin B oryzalin, respectively; but blocked jasplakinolide, stabilizer actin microfilaments. Activation or temperature, chemically modulated fluidity, cytoskeleton inhibited blocking the influx calcium. also prevented an antagonist calcium‐dependent (CDPKs). summary, our data indicate sensed structural changes plasma translates via cytoskeleton, Ca 2+ fluxes CDPKs into distinct cascades.