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Yeh CY, Wang YS, Takahashi Y, Kuusk K, Paul K, Arjus T, Yadlos O, Schroeder JI, Ilves I, Garcia-Sosa AT, Kollist H. MPK12 in stomatal CO 2 signaling: function beyond its kinase activity. New Phytol 2023. [PMID: 36978283 DOI: 10.1111/nph.18913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 03/21/2023] [Indexed: 05/24/2023]
Abstract
Protein phosphorylation is a major molecular switch involved in the regulation of stomatal opening and closure. Previous research defined interaction between MAP kinase 12 and Raf-like kinase HT1 as a required step for stomatal movements caused by changes in CO2 concentration. However, whether MPK12 kinase activity is required for regulation of CO2 -induced stomatal responses warrants in-depth investigation. We apply genetic, biochemical, and structural modeling approaches to examining the noncatalytic role of MPK12 in guard cell CO2 signaling that relies on allosteric inhibition of HT1. We show that CO2 /HCO3 - -enhanced MPK12 interaction with HT1 is independent of its kinase activity. By analyzing gas exchange of plant lines expressing various kinase-dead and constitutively active versions of MPK12 in a plant line where MPK12 is deleted, we confirmed that CO2 -dependent stomatal responses rely on MPK12's ability to bind to HT1, but not its kinase activity. We also demonstrate that purified MPK12 and HT1 proteins form a heterodimer in the presence of CO2 /HCO3 - and present structural modeling that explains the MPK12:HT1 interaction interface. These data add to the model that MPK12 kinase-activity-independent interaction with HT1 functions as a molecular switch by which guard cells sense changes in atmospheric CO2 concentration.
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Affiliation(s)
- Chung-Yueh Yeh
- Institute of Technology, University of Tartu, Nooruse 1, Tartu, 50411, Estonia
| | - Yuh-Shuh Wang
- Institute of Technology, University of Tartu, Nooruse 1, Tartu, 50411, Estonia
| | - Yohei Takahashi
- Institute of Transformative Bio-Molecules, Nagoya University, Furocho, Chikusa, Nagoya, Aichi, 464-8601, Japan
| | - Katarina Kuusk
- Institute of Technology, University of Tartu, Nooruse 1, Tartu, 50411, Estonia
| | - Karnelia Paul
- School of Biological Sciences, Cell and Developmental Biology Department, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Triinu Arjus
- Institute of Technology, University of Tartu, Nooruse 1, Tartu, 50411, Estonia
| | - Oleksii Yadlos
- Institute of Technology, University of Tartu, Nooruse 1, Tartu, 50411, Estonia
| | - Julian I Schroeder
- School of Biological Sciences, Cell and Developmental Biology Department, University of California San Diego, La Jolla, CA, 92093-0116, USA
| | - Ivar Ilves
- Institute of Technology, University of Tartu, Nooruse 1, Tartu, 50411, Estonia
| | | | - Hannes Kollist
- Institute of Technology, University of Tartu, Nooruse 1, Tartu, 50411, Estonia
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