Ebola virus nucleoprotein interaction with host protein phosphatase-1 regulates its dimerization and capsid formation
Ebola virus (EBOV) replication is regulated by the host protein phosphatases, PP1 and PP2A, which dephosphorylate the transcriptional cofactor of EBOV polymerase VP30. The PP1-targeting compound 1E7-03 induces VP30 phosphorylation and inhibits EBOV infection. Here, we investigate the broader role of PP1 in EBOV replication and transcription, including its interaction with nucleoprotein (NP). When EBOV-infected cells were continuously treated with 1E7-03, the NP E619K mutation was found and selected for further analysis. The NP E619K mutation moderately reduced the EBOV minigenome transcription, which was restored by the treatment with 1E7-03. Proteomics, immunoprecipitation, dimerization, split NanoBit, and colocalization analyses indicated that NP interacts with PP1 and that NP E619K mutations enhanced this binding. Treatment with 1E7-03 dissociated PP1-NP complex, but enhanced NP dimerization, which was more pronounced for NP E619K mutant. Mutation and deletion analyses pointed to several potential PP1-binding sites in NP that were located in the moderately disordered NP regions. When NP was co-expressed with VP24 and VP35, formation of EBOV capsids was impaired with NP E619K mutation. Treatment with 1E7-03 restored the capsid formation by the NP E619K mutant but inhibited capsids formed by WT NP. Our findings suggest that PP1 binds to NP and that this binding might regulate NP dimerization and capsid formation. Collectively, our results point to a new role for PP1 in EBOV replication, in which NP binding to PP1 may facilitate viral transcription by delaying capsid formation and EBOV replication.
Authors
- Bersabeh Tigabu
- Namita Kumari (ORCID: https://orcid.org/0000-0003-0893-9939)
- Alexander Bukreyev (ORCID: https://orcid.org/0000-0002-0342-4824)
- Victor Paromov
- Marina Jerebtsova (ORCID: https://orcid.org/0000-0001-7723-4954)
- Sergeï Nekhai (ORCID: https://orcid.org/0000-0003-0744-7887)
- Anastas Popratiloff (ORCID: https://orcid.org/0000-0002-8329-3907)
- Christine A. Brantner (ORCID: https://orcid.org/0000-0001-8172-901X)
- Tatiana Ammosova (ORCID: https://orcid.org/0000-0001-8777-1032)
- Colette Pietzsch
- А. В. Иванов (ORCID: https://orcid.org/0000-0002-1676-7754)
- Vladimir Nikolaevich Uversky (ORCID: https://orcid.org/0000-0002-4037-5857)
- Jyothirmai J. Simhadri
- Asrar Ahmad (ORCID: https://orcid.org/0000-0002-4680-0033)
- Palaniappan Ramanathan (ORCID: https://orcid.org/0000-0001-8121-7647)
- Ghadeer Abdullah
- Steve G. Widen
Institutions
- Meharry Medical College (US)
- George Washington University Hospital (US)
- Howard University (US)
- George Washington University (US)
- University of South Florida (US)
- USF Health Byrd Alzheimer's Institute (US)
- Imaging Center (US)
- The University of Texas Medical Branch at Galveston (US)
Publication Details
- Journal
- Journal of Biological Chemistry
- Published
- 2025-04-25
- DOI
- https://doi.org/10.1016/j.jbc.2025.108541
- Citations
- 1
- Primary Topic
- Viral Infections and Outbreaks Research
- Type
- article
- Field-Weighted Citation Impact
- 1.40
Funders
- National Institutes of Health
- District of Columbia Developmental Center for AIDS Research
- National Institute on Aging
- National Heart, Lung, and Blood Institute
- National Institute of Mental Health
- National Institute on Drug Abuse
- National Cancer Institute
- National Institute of General Medical Sciences
- National Institute of Allergy and Infectious Diseases
- Fogarty International Center
- National Institute of Diabetes and Digestive and Kidney Diseases
- Office of AIDS Research
- National Institute on Minority Health and Health Disparities
- Eunice Kennedy Shriver National Institute of Child Health and Human Development