E3 Ligase ITCH Interacts with the Z Matrix Protein of Lassa and Mopeia Viruses and Is Required for the Release of Infectious Particles.

Nicolas Baillet,Mathieu Mateo,Pierre-Olivier Vidalain,Xavier Carnec,Sophie Krieger,Valérie Caro,Othmann Merabet,Alexandra Journeaux,Frédéric Tangy,Sylvain Baize

doi:10.3390/v12010049

Abstract

Lassa virus (LASV) and Mopeia virus (MOPV) are two closely related, rodent-born mammarenaviruses. LASV is the causative agent of Lassa fever, a deadly hemorrhagic fever endemic in West Africa, whereas MOPV is non-pathogenic in humans. The Z matrix protein of arenaviruses is essential to virus assembly and budding by recruiting host factors, a mechanism that remains partially defined. To better characterize the interactions involved, a yeast two-hybrid screen was conducted using the Z proteins from LASV and MOPV as a bait. The cellular proteins ITCH and WWP1, two members of the Nedd4 family of HECT E3 ubiquitin ligases, were found to bind the Z proteins of LASV, MOPV and other arenaviruses. The PPxY late-domain motif of the Z proteins is required for the interaction with ITCH, although the E3 ubiquitin-ligase activity of ITCH is not involved in Z ubiquitination. The silencing of ITCH was shown to affect the replication of the old-world mammarenaviruses LASV, MOPV, Lymphocytic choriomeningitis virus (LCMV) and to a lesser extent Lujo virus (LUJV). More precisely, ITCH was involved in the egress of virus-like particles and the release of infectious progeny viruses. Thus, ITCH constitutes a novel interactor of LASV and MOPV Z proteins that is involved in virus assembly and release.

Highlights

Viral hemorrhagic fevers (VHFs) caused by mammarenaviruses represent a serious and increasing public health concern [1]
Yeast cells expressing the Z protein of Lassa virus (LASV) or Mopeia virus (MOPV) fused to GAL4-DB domain were used for screening three different libraries expressing either human or mouse proteins fused to GAL4-AD domain
We evaluated the quantity of MOPV and LASV Z-mediated virus-like particles (VLPs) release in the supernatant of ITCH-depleted or control cells transfected with a FLAG-tagged MOPV or LASV Z protein (Figure 4E)

Summary

Introduction

Viral hemorrhagic fevers (VHFs) caused by mammarenaviruses represent a serious and increasing public health concern [1]. Arenavirus-associated VHFs are zoonotic diseases, with humans acting as accidental hosts after contact with a viral reservoir, typically rodents [2]. The most prevalent pathogen among the arenaviruses is LASV, the causative agent of Lassa fever (LF), which is a significant cause of morbidity and mortality, with tens of thousands of cases annually and thousands of fatalities in. The particularity of arenaviruses is the presence of non-pathogenic agents that are not associated with human disease, despite their isolation from the same host species. This is true for Mopeia virus (MOPV), which is closely related to LASV but has never been associated to human infection [9]. MOPV has even been shown to protect non-human primates against a challenge with

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