Journal article
Phosphorylation of S344 in the calmodulin‐binding domain negatively affects CCaMK function during bacterial and fungal symbioses
The Plant journal : for cell and molecular biology, Vol.76(2), pp.287-296
10/2013
Handle:
https://hdl.handle.net/2376/104120
PMID: 23869591
Abstract
Summary
Calcium and Ca2+/calmodulin‐dependent protein kinase (CCaMK) plays a critical role in the signaling pathway that establishes root nodule symbiosis and arbuscular mycorrhizal symbiosis. Calcium‐dependent autophosphorylation is central to the regulation of CCaMK, and this has been shown to promote calmodulin binding. Here, we report a regulatory mechanism of Medicago truncatula CCaMK (MtCCaMK) through autophosphorylation of S344 in the calmodulin‐binding/autoinhibitory domain. The phospho‐ablative mutation S344A did not have significant effect on its kinase activities, and supports root nodule symbiosis and arbuscular mycorrhizal symbiosis, indicating that phosphorylation at this position is not required for establishment of symbioses. The phospho‐mimic mutation S344D show drastically reduced calmodulin‐stimulated substrate phosphorylation, and this coincides with a compromised interaction with calmodulin and its interacting partner, IPD3. Functional complementation tests revealed that the S344D mutation blocked root nodule symbiosis and reduced the mycorrhizal association. Furthermore, S344D was shown to suppress the spontaneous nodulation associated with a gain‐of‐function mutant of MtCCaMK (T271A), revealing that phosphorylation at S344 of MtCCaMK is adequate for shutting down its activity, and is epistatic over previously identified T271 autophosphorylation. These results reveal a mechanism that enables CCaMK to ‘turn off’ its function through autophosphorylation.
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Details
- Title
- Phosphorylation of S344 in the calmodulin‐binding domain negatively affects CCaMK function during bacterial and fungal symbioses
- Creators
- Pratyush Routray - Washington State UniversityJ. Benjamin Miller - John Innes CentreLiqun Du - Hangzhou Normal UniversityGiles Oldroyd - John Innes CentreB. W Poovaiah - Washington State University
- Publication Details
- The Plant journal : for cell and molecular biology, Vol.76(2), pp.287-296
- Academic Unit
- Horticulture, Department of
- Number of pages
- 10
- Grant note
- US National Science Foundation (1021344) Washington State University Agricultural Research Center National Science Foundation of China (U1130304)
- Identifiers
- 99900546977601842
- Language
- English
- Resource Type
- Journal article