AKINβγ Contributes to SnRK1 Heterotrimeric Complexes and Interacts with Two Proteins Implicated in Plant Pathogen Resistance through Its KIS/GBD Sequence
- 6 October 2006
- journal article
- Published by Oxford University Press (OUP) in Plant Physiology
- Vol. 142 (3), 931-944
- https://doi.org/10.1104/pp.106.087718
Abstract
The sucrose nonfermenting-1 protein kinase (SNF1)/AMP-activated protein kinase subfamily plays a central role in metabolic responses to nutritional and environmental stresses. In yeast (Saccharomyces cerevisiae) and mammals, the beta- and gamma-noncatalytic subunits are implicated in substrate specificity and subcellular localization, respectively, and regulation of the kinase activity. The atypical betagamma-subunit has been previously described in maize (Zea mays), presenting at its N-terminal end a sequence related to the KIS (kinase interacting sequence) domain specific to the beta-subunits (Lumbreras et al., 2001). The existence of two components, SNF1-related protein kinase (SnRK1) complexes containing the betagamma-subunit and one SnRK1 kinase, had been proposed. In this work, we show that, despite its unusual features, the Arabidopsis (Arabidopsis thaliana) homolog AKINbetagamma clearly interacts with AKINbeta-subunits in vitro and in vivo, suggesting its involvement in heterotrimeric complexes located in both cytoplasm and nucleus. Unexpectedly, a transcriptional analysis of AKINbetagamma gene expression highlighted the implication of alternative splicing mechanisms in the regulation of AKINbetagamma expression. A two-hybrid screen performed with AKINbetagamma as bait, together with in planta bimolecular fluorescence complementation experiments, suggests the existence of interactions in the cytosol between AKINbetagamma and two leucine-rich repeats related to pathogen resistance proteins. Interestingly, this interaction occurs through the truncated KIS domain that corresponds exactly to a GBD (glycogen-binding domain) recently described in mammals and yeast. A phylogenetic study suggests that AKINbetagamma-related proteins are restricted to the plant kingdom. Altogether, these data suggest the existence of plant-specific SnRK1 trimeric complexes putatively involved in a plant-specific function such as plant-pathogen interactions.Keywords
This publication has 76 references indexed in Scilit:
- SNF1-related kinases allow plants to tolerate herbivory by allocating carbon to rootsProceedings of the National Academy of Sciences, 2006
- A redox-regulated chloroplast protein phosphatase binds to starch diurnally and functions in its accumulationProceedings of the National Academy of Sciences of the United States of America, 2006
- Mutations in the Gal83 Glycogen-Binding Domain Activate the Snf1/Gal83 Kinase Pathway by a Glycogen-Independent MechanismMolecular and Cellular Biology, 2004
- Abscisic Acid and Gibberellin Differentially Regulate Expression of Genes of the SNF1-Related Kinase Complex in Tomato SeedsPlant Physiology, 2003
- AMPK β Subunit Targets Metabolic Stress Sensing to GlycogenCurrent Biology, 2003
- An activating mutation in the γ1 subunit of the AMP‐activated protein kinaseFEBS Letters, 2001
- Tree View: An application to display phylogenetic trees on personal computersBioinformatics, 1996
- Non-catalytic - and -Subunit Isoforms of the 5′-AMP-activated Protein KinaseJournal of Biological Chemistry, 1996
- Mammalian AMP-activated Protein Kinase SubfamilyJournal of Biological Chemistry, 1996
- Basic local alignment search toolJournal of Molecular Biology, 1990