RIG-I ATPase Activity and Discrimination of Self-RNA versus Non-Self-RNA

ABSTRACT Many RNA viruses are detected by retinoic acid-inducible gene i (RIG-I), a cytoplasmic sensor that triggers an antiviral response upon binding non-self-RNA that contains a stretch of double-stranded RNA (dsRNA) bearing a base-paired 5′ ppp nucleotide. To gain insight into how RIG-I discrimi...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Stéphanie Anchisi, Jessica Guerra, Dominique Garcin
Formato:	article
Lenguaje:	EN
Publicado:	American Society for Microbiology 2015
Materias:	Microbiology QR1-502
Acceso en línea:	https://doaj.org/article/2f69c082248d4abcb7dc70907c768c63
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:2f69c082248d4abcb7dc70907c768c63
record_format	dspace
spelling	oai:doaj.org-article:2f69c082248d4abcb7dc70907c768c632021-11-15T15:41:33ZRIG-I ATPase Activity and Discrimination of Self-RNA versus Non-Self-RNA10.1128/mBio.02349-142150-7511https://doaj.org/article/2f69c082248d4abcb7dc70907c768c632015-05-01T00:00:00Zhttps://journals.asm.org/doi/10.1128/mBio.02349-14https://doaj.org/toc/2150-7511ABSTRACT Many RNA viruses are detected by retinoic acid-inducible gene i (RIG-I), a cytoplasmic sensor that triggers an antiviral response upon binding non-self-RNA that contains a stretch of double-stranded RNA (dsRNA) bearing a base-paired 5′ ppp nucleotide. To gain insight into how RIG-I discriminates between self-RNA and non-self-RNA, we used duplexes whose complementary bottom strand contained both ribo- and deoxynucleotides. These duplexes were examined for their binding to RIG-I and their relative abilities to stimulate ATPase activity, to induce RIG-I dimerization on the duplex, and to induce beta interferon (IFN-β) expression. We show that the chemical nature of the bottom strand is not critical for RIG-I binding. However, two key ribonucleotides, at positions 2 and 5 on the bottom strand, are minimally required for the RIG-I ATPase activity, which is necessary but not sufficient for IFN-β stimulation. We find that duplexes with shorter stretches of dsRNA, as model self-RNAs, bind less stably to RIG-I but nevertheless have an enhanced ability to stimulate the ATPase. Moreover, ATPase activity promotes RIG-I recycling on RIG-I/dsRNA complexes. Since pseudo-self-RNAs bind to RIG-I less stably, they are preferentially recycled by ATP hydrolysis that weakens the helicase domain binding of dsRNA. Our results suggest that one function of the ATPase is to restrict RIG-I signaling to its interaction with non-self-RNA. A model of how this discrimination occurs as a function of dsRNA length is presented. IMPORTANCE The innate immune response to pathogens is based on the discrimination between self-RNA and non-self-RNA. The main determinants of this detection for RNA viruses are specific pathogen-associated molecular patterns (PAMPs) of RNA, which are detected by dedicated cytoplasmic pattern recognition receptors (PRRs). RIG-I is a PRR that specifically detects short viral dsRNAs amid a sea of cellular RNAs. Here we study the determinants of this discrimination and how RIG-I ATPase activity, the only enzymatic activity of this sensor, contributes to its activation in a manner restricted to its interaction with non-self-RNAs. We also show how the innate immune response evolves during infection via IFN expression, from a state in which discrimination of self-RNA from non-self-RNA is most important to one in which this discrimination is sacrificed for the effectiveness of the antiviral response.Stéphanie AnchisiJessica GuerraDominique GarcinAmerican Society for MicrobiologyarticleMicrobiologyQR1-502ENmBio, Vol 6, Iss 2 (2015)
institution	DOAJ
collection	DOAJ
language	EN
topic	Microbiology QR1-502
spellingShingle	Microbiology QR1-502 Stéphanie Anchisi Jessica Guerra Dominique Garcin RIG-I ATPase Activity and Discrimination of Self-RNA versus Non-Self-RNA
description	ABSTRACT Many RNA viruses are detected by retinoic acid-inducible gene i (RIG-I), a cytoplasmic sensor that triggers an antiviral response upon binding non-self-RNA that contains a stretch of double-stranded RNA (dsRNA) bearing a base-paired 5′ ppp nucleotide. To gain insight into how RIG-I discriminates between self-RNA and non-self-RNA, we used duplexes whose complementary bottom strand contained both ribo- and deoxynucleotides. These duplexes were examined for their binding to RIG-I and their relative abilities to stimulate ATPase activity, to induce RIG-I dimerization on the duplex, and to induce beta interferon (IFN-β) expression. We show that the chemical nature of the bottom strand is not critical for RIG-I binding. However, two key ribonucleotides, at positions 2 and 5 on the bottom strand, are minimally required for the RIG-I ATPase activity, which is necessary but not sufficient for IFN-β stimulation. We find that duplexes with shorter stretches of dsRNA, as model self-RNAs, bind less stably to RIG-I but nevertheless have an enhanced ability to stimulate the ATPase. Moreover, ATPase activity promotes RIG-I recycling on RIG-I/dsRNA complexes. Since pseudo-self-RNAs bind to RIG-I less stably, they are preferentially recycled by ATP hydrolysis that weakens the helicase domain binding of dsRNA. Our results suggest that one function of the ATPase is to restrict RIG-I signaling to its interaction with non-self-RNA. A model of how this discrimination occurs as a function of dsRNA length is presented. IMPORTANCE The innate immune response to pathogens is based on the discrimination between self-RNA and non-self-RNA. The main determinants of this detection for RNA viruses are specific pathogen-associated molecular patterns (PAMPs) of RNA, which are detected by dedicated cytoplasmic pattern recognition receptors (PRRs). RIG-I is a PRR that specifically detects short viral dsRNAs amid a sea of cellular RNAs. Here we study the determinants of this discrimination and how RIG-I ATPase activity, the only enzymatic activity of this sensor, contributes to its activation in a manner restricted to its interaction with non-self-RNAs. We also show how the innate immune response evolves during infection via IFN expression, from a state in which discrimination of self-RNA from non-self-RNA is most important to one in which this discrimination is sacrificed for the effectiveness of the antiviral response.
format	article
author	Stéphanie Anchisi Jessica Guerra Dominique Garcin
author_facet	Stéphanie Anchisi Jessica Guerra Dominique Garcin
author_sort	Stéphanie Anchisi
title	RIG-I ATPase Activity and Discrimination of Self-RNA versus Non-Self-RNA
title_short	RIG-I ATPase Activity and Discrimination of Self-RNA versus Non-Self-RNA
title_full	RIG-I ATPase Activity and Discrimination of Self-RNA versus Non-Self-RNA
title_fullStr	RIG-I ATPase Activity and Discrimination of Self-RNA versus Non-Self-RNA
title_full_unstemmed	RIG-I ATPase Activity and Discrimination of Self-RNA versus Non-Self-RNA
title_sort	rig-i atpase activity and discrimination of self-rna versus non-self-rna
publisher	American Society for Microbiology
publishDate	2015
url	https://doaj.org/article/2f69c082248d4abcb7dc70907c768c63
work_keys_str_mv	AT stephanieanchisi rigiatpaseactivityanddiscriminationofselfrnaversusnonselfrna AT jessicaguerra rigiatpaseactivityanddiscriminationofselfrnaversusnonselfrna AT dominiquegarcin rigiatpaseactivityanddiscriminationofselfrnaversusnonselfrna
_version_	1718427634343346176

RIG-I ATPase Activity and Discrimination of Self-RNA versus Non-Self-RNA

Ejemplares similares