Download MendeleyUnified mechanisms for self-RNA recognition by RIG-I Singleton-Merten syndrome variants.
Lassig, C., Lammens, K., Gorenflos Lopez, J.L., Michalski, S., Fettscher, O., Hopfner, K.P.(2018) Elife 7
- PubMed: 30047865
- DOI: https://doi.org/10.7554/eLife.38958
- Primary Citation of Related Structures:
6GPG - PubMed Abstract:
The innate immune sensor retinoic acid-inducible gene I (RIG-I) detects cytosolic viral RNA and requires a conformational change caused by both ATP and RNA binding to induce an active signaling state and to trigger an immune response. Previously, we showed that ATP hydrolysis removes RIG-I from lower-affinity self-RNAs (
Lässig et al., 2015 ), revealing how ATP turnover helps RIG-I distinguish viral from self-RNA and explaining why a mutation in a motif that slows down ATP hydrolysis causes the autoimmune disease Singleton-Merten syndrome (SMS). Here we show that a different, mechanistically unexplained SMS variant, C268F, which is localized in the ATP-binding P-loop, can signal independently of ATP but is still dependent on RNA. The structure of RIG-I C268F in complex with double-stranded RNA reveals that C268F helps induce a structural conformation in RIG-I that is similar to that induced by ATP. Our results uncover an unexpected mechanism to explain how a mutation in a P-loop ATPase can induce a gain-of-function ATP state in the absence of ATP.
Organizational Affiliation:
Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany.
