Ca2+/Calmodulin Activates an MAP Kinase Through the Inhibition of a Protein Phosphatase (DsPTP1) in Arabidopsis

• Published in: Journal of plant biology = Singmul Hakhoe chi Vol. 65; no. 1; pp. 65 - 74
• Main Authors: Kim, Kyung Eun, Nguyen, Nhan Thi, Kim, Sun Ho, Bahk, Sunghwa, Cheong, Mi Sun, Park, Hyeong Cheol, Lee, Kyun Oh, Hong, Jong Chan, Chung, Woo Sik
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01-02-2022; Springer Nature B.V; 한국식물학회
• Subjects: Abiotic stress; Antibodies; Binding; Biomedical and Life Sciences; Calcium ions; Calcium signalling; Calmodulin; Dephosphorylation; Environmental stress; Kinases; Life Sciences; MAP kinase; Phosphatase; Phosphorylation; Plant Breeding/Biotechnology; Plant Ecology; Plant Genetics and Genomics; Plant Sciences; Plant Systematics/Taxonomy/Biogeography; Protein phosphatase; Proteins; Research Article; Second messengers; Signal transduction; 생물학; United Kingdom > UK; Calcium; Phosphatase; Kinase; Calmodulin; Stress
• ISSN: 1226-9239; 1867-0725
• DOI: 10.1007/s12374-021-09338-x

Mitogen-activated protein kinases (MPKs) play roles as critical signal components in the environmental stress responses and developmental processes in plants. Calcium ion (Ca
2+
) is one of the most essential ubiquitous intracellular second messengers involved in many signal transduction pathways in plants. It was previously known that MPKs are activated by the increasing Ca
2+
concentration. However, the mechanism of how Ca
2+
activates MPKs is not elucidated yet. In this study, we revealed that Ca
2+
could activate MPK signaling pathway via inhibiting the activity of a dual-specificity protein phosphatase1 (DsPTP1) by Ca
2+
/calmodulin (CaM). We showed that DsPTP1 directly interacts with MPK6 in vitro and in vivo. DsPTP1 was able to inactivate the active MPK6 by dephosphorylation. Interestingly, the DsPTP1-mediated dephosphorylation of MPK6 was strongly inhibited by Ca
2+
/CaM. Moreover, this inhibition was caused by the binding of CaM to the calmodulin-binding domain II (CaMBDII) of DsPTP1. This study implies that Ca
2+
/CaM is involved in the activation of MPKs through the inhibition of DsPTP1.