Inhibition of PIKfyve kinase prevents infection by Zaire ebolavirus and SARS-CoV-2

Virus entry is a multistep process. It initiates when the virus attaches to the host cell and ends when the viral contents reach the cytosol. Genetically unrelated viruses can subvert analogous subcellular mechanisms and use similar trafficking pathways for successful entry. Antiviral strategies targeting early steps of infection are therefore appealing, particularly when the probability for successful interference through a common step is highest. We describe here potent inhibitory effects on content release and infection by chimeric VSV containing the envelope proteins of Zaire ebolavirus (VSV-ZEBOV) or SARS-CoV-2 (VSV-SARS-CoV-2) elicited by Apilimod and Vacuolin-1, small molecule inhibitors of the main endosomal Phosphatidylinositol-3-Phosphate/Phosphatidylinositol 5-Kinase, PIKfyve. We also describe potent inhibition of SARS-CoV-2 strain 2019-nCoV/USA-WA1/2020 by Apilimod. These results define new tools for studying the intracellular trafficking of pathogens elicited by inhibition of PIKfyve kinase and suggest the potential for targeting this kinase in developing small-molecule antivirals against SARS-CoV-2.

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Inhibition of PIKfyve kinase prevents infection by Zaire ebolavirus and SARS-CoV-2

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.2007837117 ◽

2020 ◽

Vol 117 (34) ◽

pp. 20803-20813 ◽

Cited By ~ 15

Author(s):

Yuan-Lin Kang ◽

Yi-ying Chou ◽

Paul W. Rothlauf ◽

Zhuoming Liu ◽

Timothy K. Soh ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Vesicular Stomatitis Virus ◽

Small Molecule ◽

Intracellular Trafficking ◽

Virus Entry ◽

Inhibitory Effects ◽

Potent Inhibition ◽

Multistep Process ◽

Zaire Ebolavirus ◽

Vesicular Stomatitis

Virus entry is a multistep process. It initiates when the virus attaches to the host cell and ends when the viral contents reach the cytosol. Genetically unrelated viruses can subvert analogous subcellular mechanisms and use similar trafficking pathways for successful entry. Antiviral strategies targeting early steps of infection are therefore appealing, particularly when the probability for successful interference through a common step is highest. We describe here potent inhibitory effects on content release and infection by chimeric vesicular stomatitis virus (VSV) containing the envelope proteins of Zaire ebolavirus (VSV-ZEBOV) or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) (VSV-SARS-CoV-2) elicited by Apilimod and Vacuolin-1, small-molecule inhibitors of the main endosomal phosphatidylinositol-3-phosphate/phosphatidylinositol 5-kinase, PIKfyve. We also describe potent inhibition of SARS-CoV-2 strain 2019-nCoV/USA-WA1/2020 by Apilimod. These results define tools for studying the intracellular trafficking of pathogens elicited by inhibition of PIKfyve kinase and suggest the potential for targeting this kinase in developing small-molecule antivirals against SARS-CoV-2.

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Small Molecule Inhibitors of Influenza Virus Entry

Pharmaceuticals ◽

10.3390/ph14060587 ◽

2021 ◽

Vol 14 (6) ◽

pp. 587

Author(s):

Zhaoyu Chen ◽

Qinghua Cui ◽

Michael Caffrey ◽

Lijun Rong ◽

Ruikun Du

Keyword(s):

Influenza Virus ◽

Membrane Fusion ◽

Small Molecule ◽

Drug Target ◽

Small Molecule Inhibitors ◽

Virus Entry ◽

Critical Role ◽

Structural Basis ◽

Future Directions ◽

The Past

Hemagglutinin (HA) plays a critical role during influenza virus receptor binding and subsequent membrane fusion process, thus HA has become a promising drug target. For the past several decades, we and other researchers have discovered a series of HA inhibitors mainly targeting its fusion machinery. In this review, we summarize the advances in HA-targeted development of small molecule inhibitors. Moreover, we discuss the structural basis and mode of action of these inhibitors, and speculate upon future directions toward more potent inhibitors of membrane fusion and potential anti-influenza drugs.

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Release of gp120 Restraints Leads to an Entry-Competent Intermediate State of the HIV-1 Envelope Glycoproteins

mBio ◽

10.1128/mbio.01598-16 ◽

2016 ◽

Vol 7 (5) ◽

Cited By ~ 59

Author(s):

Alon Herschhorn ◽

Xiaochu Ma ◽

Christopher Gu ◽

John D. Ventura ◽

Luis Castillo-Menendez ◽

...

Keyword(s):

Small Molecule ◽

Intermediate State ◽

Neutralizing Antibodies ◽

Small Molecule Inhibitors ◽

Virus Entry ◽

Envelope Glycoproteins ◽

Low Levels ◽

State 1 ◽

Hiv 1 ◽

Conformation State

ABSTRACTPrimary human immunodeficiency virus (HIV-1) envelope glycoprotein (Env) trimers [(gp120/gp41)3] typically exist in a metastable closed conformation (state 1). Binding the CD4 receptor triggers Env to undergo extensive conformational changes to mediate virus entry. We identified specific gp120 residues that restrain Env in state 1. Alteration of these restraining residues destabilized state 1, allowing Env to populate a functional conformation (state 2) intermediate between state 1 and the full CD4-bound state (state 3). Increased state 2 occupancy was associated with lower energy barriers between the states. State 2 was an obligate intermediate for all transitions between state 1 and state 3. State 2-enriched Envs required lower CD4 concentrations to trigger virus entry and more efficiently infected cells expressing low levels of CD4. These Envs were resistant to several broadly neutralizing antibodies and small-molecule inhibitors. Thus, state 2 is an Env conformation on the virus entry pathway; sampling state 2 increases the adaptability of HIV-1 to different host cell receptor levels and immune environments. Our results provide new insights into the conformational regulation of HIV-1 entry.IMPORTANCEThe envelope glycoproteins (Env) of HIV-1 mediate virus entry and are the sole targets of neutralizing antibodies. Understanding the way that Env promotes HIV-1 entry can expedite drug and vaccine development. By destabilizing Env, we found that it assumes an intermediate state that is functional and obligate for transitions to entry-competent conformations. Increased sampling of this state enhances the ability of HIV-1 to infect cells that express low levels of the CD4 receptor and allows the virus to evade neutralizing antibodies and small-molecule inhibitors. These findings provide new mechanistic insights into the function and inhibition of HIV-1 Env and will contribute to ongoing therapeutic and prevention efforts to combat HIV-1.

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