NEDD4 family ubiquitin ligases associate with LCMV Z’s PPXY domain and are required for virus budding, but not via direct ubiquitination of Z

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...

Section: Discussionsupporting

confidence: 93%

“…This observation is in accordance with a recent study in which authors showed that three Nedd4 family proteins (Nedd4, WWP1, and ITCH) bind the PPxY domain of LCMV and JUNV Z protein. Although this interaction resulted in ubiquitination of Z in transfection condition, Z ubiquitination was also dispensable for virus particle release [66].…”

Section: Discussionmentioning

confidence: 96%

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

Baillet

Krieger

Carnec

et al. 2019

“…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 ].…”

Section: Viral Factors Involved In Entry To the Escrt Pathwaymentioning

confidence: 99%

“…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 ].…”

Section: Viral Factors Involved In Entry To the Escrt Pathwaymentioning

confidence: 99%

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

Meng

Lever

2021

Viruses are obligate parasites that rely on host cellular factors to replicate and spread. The endosomal sorting complex required for transport (ESCRT) system, which is classically associated with sorting and downgrading surface proteins, is one of the host machineries hijacked by viruses across diverse families. Knowledge gained from research into ESCRT and viruses has, in turn, greatly advanced our understanding of many other cellular functions in which the ESCRT pathway is involved, e.g., cytokinesis. This review highlights the interplay between the ESCRT pathway and the viral factors of enveloped viruses with a special emphasis on retroviruses.

“…They demonstrated that these ligases ubiquitinate LCMV Z, a process that was dispensable for virus release but needed for defective interfering (DI) particle release. These data infer that ubiquitination of other cellular or viral targets than the Z protein by Nedd4 ligases may be the essential link to the ESCRT machinery and enhancement of viral budding [ 181 ]. Alongside ubiquitination as a regulator of viral budding, Ziegler and colleagues identified two phosphorylation sites, Y97 and S98 (LASV numbering), located at the C-terminal tail of protein Z and overlapping with the late domain region that could also influence Z protein function.…”

Section: Evasion Strategies Of the Arenavirus Matrix Protein Zmentioning

confidence: 99%

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

Stott

Strecker

Foster

2020

Endemic to West Africa and South America, mammalian arenaviruses can cross the species barrier from their natural rodent hosts to humans, resulting in illnesses ranging from mild flu-like syndromes to severe and fatal haemorrhagic zoonoses. The increased frequency of outbreaks and associated high fatality rates of the most prevalent arenavirus, Lassa, in West African countries, highlights the significant risk to public health and to the socio-economic development of affected countries. The devastating impact of these viruses is further exacerbated by the lack of approved vaccines and effective treatments. Differential immune responses to arenavirus infections that can lead to either clearance or rapid, widespread and uncontrolled viral dissemination are modulated by the arenavirus multifunctional proteins, NP and Z. These two proteins control the antiviral response to infection by targeting multiple cellular pathways; and thus, represent attractive targets for antiviral development to counteract infection. The interplay between the host immune responses and viral replication is a key determinant of virus pathogenicity and disease outcome. In this review, we examine the current understanding of host immune defenses against arenavirus infections and summarise the host protein interactions of NP and Z and the mechanisms that govern immune evasion strategies.