Molecular identification of phenylalanine ammonia‐lyase as a substrate of a specific constitutively activeArabidopsisCDPK expressed in maize protoplasts
- 14 August 2001
- journal article
- Published by Wiley in FEBS Letters
- Vol. 503 (2-3) , 185-188
- https://doi.org/10.1016/s0014-5793(01)02732-6
Abstract
Phenylalanine ammonia-lyase (PAL) is a key enzyme in pathogen defence, stress response and secondary metabolism and is subject to post-translational phosphorylation. In order to address the significance of this phenomenon it is necessary to identify the protein kinase (PK) responsible and place it in its regulatory circuit. Using protoplast transient expression of Arabidopsis kinase genes coupled to immunocomplex kinase assay, it has been possible to screen for specific PAL kinase. We show here that AtCPK1 (calcium dependent PK), but not other closely related PKs could phosphorylate both a recombinant PAL protein and a peptide (SRVAKTRTLTTA) that is a site phosphorylated in vivo. Identification of the specific CDPK as a PAL kinase now opens up the possibility of exploring the calcium link in biotic stress signalling, salicylate and phytoalexin production as well as the significance of PAL phosphorylation. The protoplast transient expression system is a potentially powerful method to determine and screen for plant gene functions utilising genomic and proteomic data.Keywords
This publication has 23 references indexed in Scilit:
- Resistance Gene-Dependent Activation of a Calcium-Dependent Protein Kinase in the Plant Defense ResponsePlant Cell, 2000
- CDPKs – a kinase for every Ca2+ signal?Trends in Plant Science, 2000
- Transgene-Mediated and Elicitor-Induced Perturbation of Metabolic Channeling at the Entry Point into the Phenylpropanoid PathwayPlant Cell, 1999
- Engineered GFP as a vital reporter in plantsCurrent Biology, 1996
- Activation of a Ca2+-Dependent Protein Kinase Involves Intramolecular Binding of a Calmodulin-like Regulatory DomainBiochemistry, 1996
- Intramolecular Binding Contributes to the Activation of CDPK, a Protein Kinase with a Calmodulin-Like DomainBiochemistry, 1996
- Pseudosubstrate Inhibition of CDPK, a Protein Kinase with a Calmodulin-like DomainBiochemistry, 1994
- Characterization of an Arabidopsis Calmodulin-like Domain Protein Kinase Purified from Escherichia coli Using an Affinity Sandwich TechniqueBiochemistry, 1994
- Calcium and lipid regulation of an Arabidopsis protein kinase expressed in Escherichia coliBiochemistry, 1993
- A role for phosphorylation in the down-regulation of phenylalanine ammonia-lyase in suspension-cultured cells of french beanPhytochemistry, 1992