# Determinants of viral assembly and infectivity within the Ebola virus VP24 protein

> **NIH AI R01** · ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI · 2026 · $843,182

## Abstract

Summary
Ebola virus (EBOV), a filovirus, causes periodic outbreaks with high fatality rates. To understand the basis for
viral pathogenesis, emergence, and to devise control strategies, it is important to define the mechanisms that
underlie EBOV assembly and release of infectious virus. The VP24 protein, produced by one of seven viral
genes, is a 24 kDa multifunctional protein unique to the filovirus family. EBOV VP24 blocks cellular responses to
interferons (IFN) by preventing nuclear translocation of tyrosine phosphorylated STAT1 (pSTAT1), a transcription
factor central to antiviral IFN signaling. VP24 accomplishes this by interacting with importin α (IMPA) nuclear
transport proteins, preventing binding and nuclear import of STAT1, a key transcription factor needed for IFN
responses. That VP24 interacts with IMPA nuclear import factors suggests that VP24 can traffic into the nucleus.
In addition, transfection studies identified a nuclear export signal (NES) at the C-terminus of EBOV VP24, further
supporting nuclear its trafficking. However, whether EBOV VP24 undergoes nucleocytoplasmic trafficking and
the functional significance of this trafficking remain to be determined. VP24 also plays a critical but incompletely
understood role in viral genome packaging and production of infectious viral particles. Most notably, VP24, the
EBOV nucleoprotein and EBOV VP35 together form filamentous nucleocapsid structures, called nucleocapsid-
like structures (NCLS) that are morphologically indistinguishable from the nucleocapsids present in EBOV
virions. The presence of VP24 also renders NCLS competent for actin-dependent transport. Fundamental
questions remain including how VP24 facilitates actin-dependent transport and the specific molecular features
required for NCLS formation and trafficking. Our Preliminary Data indicates that VP24 can traffic into and out of
the nucleus and that disruption of IMPA binding significantly impairs virus growth at a late stage in the replicati

## Key facts

- **NIH application ID:** 11319583
- **Project number:** 1R01AI197393-01
- **Recipient organization:** ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
- **Principal Investigator:** Christopher F Basler; Daisy W Leung
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** AI
- **Fiscal year:** 2026
- **Award amount:** $843,182
- **Award type:** 1
- **Project period:** 2026-04-16T00:00:00 → 2031-03-31T00:00:00

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11319583

## Citation

> US National Institutes of Health, RePORTER application 11319583, Determinants of viral assembly and infectivity within the Ebola virus VP24 protein (1R01AI197393-01). Retrieved via AI Analytics 2026-07-04 from https://api.ai-analytics.org/grant/nih/11319583. Licensed CC0.

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