Dredd-mediated cleavage of Kenny uncouples the IKK complex from selective autophagy to enable innate immunity

Read the full article See related articles

Discuss this preprint

Start a discussion What are Sciety discussions?

Listed in

This article is not in any list yet, why not save it to one of your lists.
Log in to save this article

Abstract

Selective autophagy restrains innate immune signalling to maintain tissue homeostasis, yet how this repression is rapidly relieved during infection remains unclear. Here, we show that under basal conditions the inhibitor of κB kinase γ (IKKγ) Kenny is sequestered at autophagosomes through Atg8 and the selective autophagy receptor Ref(2)P, thereby silencing Imd pathway activity. Bacterial infection disrupts this interaction, releasing the IKK complex to enable immune signalling. Mechanistically, we identify the initiator caspase Dredd as a direct interactor of the IKKγ Kenny and show that Dredd binds and cleaves Kenny in a ubiquitination-dependent manner during infection. This cleavage removes an N-terminal LC3-interacting region, uncoupling the IKK complex from autophagosomal degradation. Dredd-mediated processing of Kenny stabilises the IKK complex and is required for activation of the NF-κB transcription factor Relish, robust antibacterial responses, and host survival following infection. Together, these findings uncover a mechanism by which caspase-mediated cleavage intersects with selective autophagy to dynamically control NF-κB signalling during bacterial infection.

Short summary

Bacterial infection activates NF-κB signalling by triggering caspase-dependent cleavage of the IKK subunit Kenny, releasing the IKK complex from autophagosomal repression to enable effective innate immune responses.

Article activity feed