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

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.Viruses 2020, 12, 49 2 of 20 arenavirus complex known to cause VHF includes Lassa virus (LASV) and the recently discovered Lujo virus (LUJV) [3,4]. The prototypic arenavirus, lymphocytic choriomeningitis virus (LCMV), which is distributed worldwide, is also of clinical significance [5]. 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 West Africa [6]. The disease is characterized by acute forms associated with fever, myalgia, abdominal pain, nausea, diarrhea, cough, sore throat, and facial edema and evolves toward a shock syndrome in the terminal stage for severe cases. The tendency of LASV to cause outbreaks has steadily risen in Nigeria over the last three years, with laboratory-confirmed cases increasing from 106 in 2016 to 143 in 2017 and reaching 562 by November 2018 [7]. Additionally, there is currently no licensed vaccine or efficient antiviral drug available in the field against this disease, for which the area of endemicity is expanding [8]. 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 LASV, showing that both viruses are antigenically related. Comparing LASV and MOPV should therefore allow the identification of immune and viral features involved in LF pathogenesis and, to a lesser extent, other arenavirus-associated VHFs.The bi-s...

The Interplay between ESCRT and Viral Factors in the Enveloped Virus Life Cycle

“…Filoviruses (e.g., Ebola and Marburg [ 98 ]) and rhabdoviruses (e.g., vesicular stomatitis virus (VSV [ 99 ])) also encode a PPXY motif in their VP40 and M proteins, respectively, that specifically interacts with WW domain containing proteins to facilitate viral release. Arenaviruses also encode a PPXY domain in their matrix Z protein [ 100 ], through which the NEDD4 ligase is recruited [ 101 , 102 ]. However, ubiquitination of the PPXY-containing Z protein of LCMV itself is insufficient for virus budding, suggesting factors other than Z is involved [ 101 ].…”

Distinct Molecular Mechanisms of Host Immune Response Modulation by Arenavirus NP and Z Proteins

“…In the case of NW TCRV and OW MOPV, the YxxL motif does not contribute to the self-budding activity of Z, but it is critical for NP-mediated enhancement of Z-driven VLP budding as well as the incorporation of NP into VLPs [ 97 , 177 , 179 ]. Using a yeast two-hybrid screen, Baillet and colleagues recently uncovered the interaction of two members of the Nedd4 family of HECT E3 ubiquitin ligases, ITCH and WWP1 with Z proteins of MOPV and LASV [ 180 ]. They observed that ITCH was needed for efficient production of infectious virus particles of LCMV, LASV, LUJV and MOPV; and found that direct interaction with this pro-viral host factor was dependent on the PPxY late domain of LASV and MOPV.…”

“…They observed that ITCH was needed for efficient production of infectious virus particles of LCMV, LASV, LUJV and MOPV; and found that direct interaction with this pro-viral host factor was dependent on the PPxY late domain of LASV and MOPV. Thus, this host protein acts as a positive regulator of the late stages of virus infection by enhancing the processes of viral release and virus production [ 180 ]. Independently, a proteomics study conducted by Ziegler and colleagues identified Nedd4 family ubiquitin ligases, including ITCH and WWP1, as partners of the LCMV Z protein, binding specifically to the PPxY motif of LCMV Z.…”

SARS-CoV-2 Encodes a PPxY Late Domain Motif Known to Enhance Budding and Spread in Enveloped RNA Viruses

“…The PPxY L-domain motif is known to interact with proteins containing WW-domain(s). L-domain motifs have been identified in single-stranded enveloped RNA viruses (Table 1), including in the Gag proteins of several retroviruses and in the matrix of arenaviruses, rhabdoviruses and filoviruses (Baillet et al, 2019;Bieniasz, 2006;Wirblich et al, 2008). RNA viruses use PPxY L-domain motifs to recruit specific WW-domains of host Nedd4 family members and ultimately the ESCRT complex to facilitate their budding and egress (Bieniasz, 2006).…”

“…The term "Late" reflects a late function in the virus life cycle (Garnier et al, 1996;Freed, 2002). L-domain motifs are identified in enveloped RNA viruses such as in the Gag protein of a number of retroviruses and in the matrix of arenaviruses, rhabdoviruses and filoviruses (Baillet et al, 2019;Bieniasz, 2006;Wirblich et al, 2008). The WW-domain is a small domain of 35-40 amino acids, named after two conserved tryptophan (W) residues in the sequence (Bork and Sudol, 1994).…”