Interferon-induced IFITM recruitment of ZMPSTE24 blocks viral endocytic entry Abstract Viruses must penetrate the cell?s protective phospholipid bilayer to initiate the infectious process. Enveloped viruses enter the cytoplasm by a membrane fusion mechanism often via an endolysosomal route. Interferon- inducible transmembrane proteins (IFITM) were shown to block a broad spectrum of RNA viruses with endocytic entry. However, how IFITM proteins inhibit viral entry is not clear. This application proposes that ZMPSTE24 (abbreviated ZMP), an evolutionarily conserved membrane associated zinc metalloprotease, is a broad-spectrum antiviral effector downstream of IFITM. Preliminary data suggest that type I interferon (IFN) induces IFITM proteins, which in turn recruit and retain ZMP on endosomes. Experiments involving overexpression and genetic deficiency indicate ZMP has antiviral activity against RNA and DNA viruses, including influenza A virus (IAV), vesicular stomatitis virus (VSV) and vaccinia virus (VACV). Direct viral entry assays using virus-like particles suggest ZMP restricts viral endosomal entry. To understand how ZMP functions, this proposal probes the molecular mechanism controlling ZMP cooperation with IFITM proteins.
Aim 1 will determine how ZMP and IFITM cooperate and if either can function independently to restrict viral infection. Critical residues involved in ZMP-IFITM interaction and antiviral function are identified.
Aim 2 examines the antiviral requirement for ZMP in vivo using an IAV model in zmp-/- mice. Model systems to investigate the role of ZMP deficiency in human cells are proposed.
Aim 3 investigates the molecular mechanisms underlying ZMP blockade of viral entry. The role of ZMP in membrane hemifusion will be characterized. Additional studies examine ZMP dimerization and use AP-MS to identify ZMP interacting molecules which regulate antiviral function. In summary, this project will characterize the IFITM-ZMP antiviral signaling cascade and provide an improved understanding of innate antiviral defense.

Public Health Relevance

Lay summary. Virus entry is the first step of infection; thereby impeding virus at the entry point is important for host defense. This proposal presents the discovery of a broad-spectrum antiviral protein which impedes virus entry.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI121288-02
Application #
9317424
Study Section
Immunity and Host Defense (IHD)
Program Officer
Hauguel, Teresa M
Project Start
2016-07-20
Project End
2020-06-30
Budget Start
2017-07-01
Budget End
2018-06-30
Support Year
2
Fiscal Year
2017
Total Cost
Indirect Cost
Name
Harvard Medical School
Department
Internal Medicine/Medicine
Type
Schools of Medicine
DUNS #
047006379
City
Boston
State
MA
Country
United States
Zip Code
02115
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Fu, Bishi; Wang, Lingyan; Li, Shitao et al. (2017) ZMPSTE24 defends against influenza and other pathogenic viruses. J Exp Med 214:919-929
Wang, Lingyan; Fu, Bishi; Li, Wenjun et al. (2017) Comparative influenza protein interactomes identify the role of plakophilin 2 in virus restriction. Nat Commun 8:13876
Li, Shitao; Fu, Bishi; Wang, Lingyan et al. (2017) ZMPSTE24 Is Downstream Effector of Interferon-Induced Transmembrane Antiviral Activity. DNA Cell Biol 36:513-517