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A Regulatory Module Controlling Homeostasis of a Plant Immune Kinase.
- Source :
-
Molecular Cell . Feb2018, Vol. 69 Issue 3, p493-504.e6. 1p. - Publication Year :
- 2018
-
Abstract
- Summary Plant pattern recognition receptors (PRRs) perceive microbial and endogenous molecular patterns to activate immune signaling. The cytoplasmic kinase BIK1 acts downstream of multiple PRRs as a rate-limiting component, whose phosphorylation and accumulation are central to immune signal propagation. Previous work identified the calcium-dependent protein kinase CPK28 and heterotrimeric G proteins as negative and positive regulators of BIK1 accumulation, respectively. However, mechanisms underlying this regulation remain unknown. Here we show that the plant U-box proteins PUB25 and PUB26 are homologous E3 ligases that mark BIK1 for degradation to negatively regulate immunity. We demonstrate that the heterotrimeric G proteins inhibit PUB25/26 activity to stabilize BIK1, whereas CPK28 specifically phosphorylates conserved residues in PUB25/26 to enhance their activity and promote BIK1 degradation. Interestingly, PUB25/26 specifically target non-activated BIK1, suggesting that activated BIK1 is maintained for immune signaling. Our findings reveal a multi-protein regulatory module that enables robust yet tightly regulated immune responses. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10972765
- Volume :
- 69
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- Molecular Cell
- Publication Type :
- Academic Journal
- Accession number :
- 127640657
- Full Text :
- https://doi.org/10.1016/j.molcel.2017.12.026