EXO70D isoforms mediate selective autophagic degradation of type-A ARR proteins to regulate cytokinin sensitivity
| Autor: | Atiako Kwame Acheampong, Yasin F. Dagdas, Chai-Yi Chang, Carly Shanks, G. Eric Schaller, Joseph J. Kieber |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Senescence
Gene isoform Cytokinins Multidisciplinary biology Arabidopsis Proteins Chemistry ATG8 fungi Autophagy Mutant Arabidopsis food and beverages Autophagy-Related Protein 8 Family Biological Sciences biology.organism_classification Cell biology chemistry.chemical_compound Stress Physiological Cytokinin Phosphorylation Receptor |
| Zdroj: | Proc Natl Acad Sci U S A |
| ISSN: | 1091-6490 0027-8424 |
| DOI: | 10.1073/pnas.2013161117 |
| Popis: | The phytohormone cytokinin influences many aspects of plant growth and development, several of which also involve the cellular process of autophagy, including leaf senescence, nutrient re-mobilization, and developmental transitions. The Arabidopsis type-A Response Regulators (type-A ARR) are negative regulators of cytokinin signaling that are transcriptionally induced in response to cytokinin. Here, we describe a mechanistic link between cytokinin signaling and autophagy, demonstrating that plants modulate cytokinin sensitivity through autophagic regulation of type-A ARR proteins. Type-A ARR proteins were degraded by autophagy in an AUTOPHAGY-RELATED (ATG)5-dependent manner. EXO70D family members interacted with Type-A ARR proteins, likely in a phosphorylation-dependent manner, and recruited them to autophagosomes via interaction with the core autophagy protein, ATG8. Consistently, loss-of-function exo70D1,2,3 mutants compromised targeting of type-A ARRs to autophagic vesicles, have elevated levels of type-A ARR proteins, and are hyposensitive to cytokinin. Disruption of both type-A ARRs and EXO70D1,2,3 compromised survival in carbon-deficient conditions, suggesting interaction between autophagy and cytokinin responsiveness in response to stress. These results indicate that the EXO70D proteins act as selective autophagy receptors to target type-A ARR cargos for autophagic degradation, demonstrating that cytokinin signaling can be modulated by selective autophagy. |
| Databáze: | OpenAIRE |
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