Ubiquitin-Mediated Regulation of the Pattern-Recognition Receptor OsCERK1 Activates Immune Signaling in Rice

Temel Kavramlar

The U-box ubiquitin E3 ligase OsCIE1 acts as a molecular brake to inhibit the pattern-recognition receptor kinase OsCERK1 in rice, and its phosphorylation-dependent inactivation releases the brake to promote immune signaling.

Özet

The article investigates the regulatory mechanisms that control the activation of the pattern-recognition receptor kinase OsCERK1, which is essential for plant immunity against microbial pathogens. The authors find that the U-box ubiquitin E3 ligase OsCIE1 acts as a molecular brake to inhibit OsCERK1 during homeostasis.

During normal conditions, OsCIE1 ubiquitinates OsCERK1, reducing its kinase activity and preventing autoimmunity. However, in the presence of the microbial pattern molecule chitin, active OsCERK1 phosphorylates OsCIE1, blocking its E3 ligase activity. This phosphorylation-dependent inactivation of OsCIE1 releases the brake on OsCERK1, allowing it to promote immune signaling and plant defense responses.

The authors further show that the phosphorylation of a specific serine residue within the U-box of OsCIE1 prevents its interaction with E2 ubiquitin-conjugating enzymes, serving as a phosphorylation switch that regulates the E3 ligase activity. Interestingly, this phosphorylation site is conserved in E3 ligases from plants to animals, suggesting a common regulatory mechanism.

The study identifies a ligand-released brake mechanism that enables dynamic and tightly controlled regulation of pattern-recognition receptor activation, which is crucial for effective immune responses while preventing autoimmunity.

İstatistikler

The microorganism-associated molecular pattern chitin activates OsCERK1 kinase activity.
Phosphorylation of a serine residue within the U-box of OsCIE1 prevents its interaction with E2 ubiquitin-conjugating enzymes.

Alıntılar

"During homeostasis, OsCIE1 ubiquitinates OsCERK1, reducing its kinase activity."
"In the presence of the microorganism-associated molecular pattern chitin, active OsCERK1 phosphorylates OsCIE1 and blocks its E3 ligase activity, thus releasing the brake and promoting immunity."
"Phosphorylation of a serine within the U-box of OsCIE1 prevents its interaction with E2 ubiquitin-conjugating enzymes and serves as a phosphorylation switch."

Önemli Bilgiler Şuradan Elde Edildi

Release of a ubiquitin brake activates OsCERK1-triggered immunity in rice - Nature

by Gang Wang,Xi... : www.nature.com 05-15-2024

https://www.nature.com/articles/s41586-024-07418-9

Daha Derin Sorular

How might this ubiquitin-mediated regulatory mechanism of pattern-recognition receptor activation be exploited for engineering enhanced disease resistance in crop plants?

The ubiquitin-mediated regulatory mechanism described in the context can be harnessed for engineering enhanced disease resistance in crop plants by manipulating the activity of E3 ligases that act as molecular brakes on pattern-recognition receptors. By understanding the specific interactions and phosphorylation events that lead to the release of the brake and activation of immune signaling, researchers can potentially engineer plants with modified E3 ligases that respond more efficiently to pathogen attacks. This could involve designing E3 ligases with altered phosphorylation sites to enhance their inactivation upon pathogen detection, thereby boosting the plant's immune response. Additionally, targeted genetic modifications could be employed to fine-tune the ubiquitination process, leading to a more rapid and robust activation of immune pathways in crop plants.

What other cellular processes or signaling pathways might be regulated by similar phosphorylation-dependent inactivation of E3 ubiquitin ligases?

Phosphorylation-dependent inactivation of E3 ubiquitin ligases could potentially regulate a wide range of cellular processes and signaling pathways beyond immune signaling. For instance, E3 ligases play crucial roles in the regulation of cell cycle progression, DNA repair, protein degradation, and receptor signaling. By modulating the phosphorylation status of E3 ligases, these processes could be finely tuned in response to various stimuli or environmental cues. In the context of receptor signaling, similar mechanisms could control the activation of growth factor receptors, hormone receptors, or stress response pathways. Moreover, the phosphorylation-dependent inactivation of E3 ligases may also impact developmental processes, such as differentiation, tissue growth, and organ formation, by regulating the stability and activity of key regulatory proteins.

Given the conservation of the phosphorylation site in E3 ligases across plants and animals, what evolutionary advantages does this regulatory mechanism provide, and how might it be involved in other biological processes beyond immune signaling?

The conservation of the phosphorylation site in E3 ligases across plants and animals suggests that this regulatory mechanism provides significant evolutionary advantages in coordinating cellular responses to diverse stimuli. By utilizing a common phosphorylation switch to modulate E3 ligase activity, organisms can rapidly adapt to changing environmental conditions and fine-tune their cellular processes. Beyond immune signaling, this regulatory mechanism may be involved in various biological processes, such as stress responses, metabolic regulation, and developmental pathways. For example, in stress responses, phosphorylation-dependent inactivation of E3 ligases could regulate the turnover of stress-responsive proteins, allowing the cell to mount an appropriate defense mechanism. In metabolic regulation, this mechanism could control the degradation of key enzymes or signaling molecules in response to nutrient availability. Overall, the evolutionary conservation of this regulatory mechanism highlights its importance in orchestrating diverse biological processes across different organisms.