Hydrogen peroxide is a regulator of ABI1, a protein phosphatase 2C from Arabidopsis

FEBS Letters

Meinhard, Michael¹  Grill, Erwin¹ 

[1]Lehrstuhl für Botanik, Technische Universität München, Biologikum Weihenstephan, Am Hochanger 4, 85354 Freising, Germany

关键词: Abscisic acid;    Protein phosphatase 2C;    Plant hormone;    Signalling;    Arabidopsis;    IC50;    inhibition constant;    MUP;    methylumbelliferylphosphate;    PAO;    phenylarsine oxide;    PP;    protein phosphatase;    PP2C;    protein phosphatase 2C;   

DOI  :  10.1016/S0014-5793(01)03106-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Protein phosphatases 2C (PP2Cs) exhibit diverse regulatory functions in signalling pathways of animals, yeast and plants. ABI1 is a PP2C of Arabidopsis that exerts negative control on signalling of the phytohormone abscisic acid (ABA). Characterisation of the redox sensitivity of ABI1 revealed a strong enzymatic inactivation by hydrogen peroxide (H₂O₂) which has recently been implicated as a secondary messenger of ABA signalling. H₂O₂ reversibly inhibited ABI1 activity in vitro with an IC₅₀ of approximately 140 μM in the presence of physiological concentrations of glutathione. In addition, ABI1 was highly susceptible to inactivation by phenylarsine oxide (IC₅₀=3–4 μM) indicative for the facile oxidation of vicinal cysteine residues. Thus, H₂O₂ generated during ABA signalling seems to inactivate the negative regulator of the ABA response.

【 授权许可】

Unknown