# Investigating the role of ubiquitination in regulating viral RNA processing during Adenovirus infection

> **NIH NIH F32** · CHILDREN'S HOSP OF PHILADELPHIA · 2020 · $69,306

## Abstract

Project Summary
 Viruses have a limited genome and, therefore, must commandeer host cell processes in order to mount
a productive infection. One way viruses manipulate host processes is by hijacking the cellular ubiquitin system
in order to redirect ubiquitination of host proteins. Ubiquitination is a protein post-translational modification in
which an E3 ubiquitin ligase enzyme catalyzes the attachment of a ubiquitin molecule to a protein substrate. The
most well understood outcome of ubiquitination is targeting the substrate for proteasomal degradation. However,
it has become increasingly appreciated that ubiquitination can also direct functional outcomes other than
degradation, such as altering protein function, location or interactions. It is well known that viruses redirect
cellular ubiquitination in order to degrade host anti-viral factors. However, there is a gap in knowledge as to
whether and how viruses use alternative functions of ubiquitin to control cellular processes during infection.
 Human Adenovirus (AdV) offers a compelling system in which to study viral-mediated ubiquitination
because it is known to redirect ubiquitination of host proteins to support infection but the range of targeted
substrates is unknown. AdV encodes two viral proteins, E1B55K and E4orf6, that complex with host proteins to
form a viral E3 ubiquitin ligase. AdV lacking a functional E1B55K/E4orf6 ligase exhibits RNA processing
deficiencies. However, the known substrates of the viral ubiquitin ligase can not explain the mechanistic link
between the ligase and viral RNA processing. I propose that there are unknown substrates of the E1B55K/E4orf6
ubiquitin ligase that impact viral RNA processing. I analyzed ubiquitin-proteomics datasets to identify unknown
E1B55K/E4orf6 substrates. The predicted substrates are enriched for RNA-binding proteins, which are
potentially important to describe the ligase function in viral RNA processing. Furthermore, the RNA-binding
substrates are ubiquitinated but not decreased in abundance, suggesting that this analysis identifies the first
known examples of AdV non-degradative ubiquitination. Additional preliminary data suggest that deletion of the
E1B55K/E4orf6 ligase decreases viral RNA splicing efficiency. Therefore, I propose to define the role of AdV-
mediated ubiquitination in viral RNA processing through two specific aims that combine experimental and
bioinformatics approaches. I will 1) examine the protein-protein and protein-RNA interactions of the RNA-
binding substrates of E1B55K/E4orf6 and 2) examine the impact of E1B55K/E4orf6 on viral RNA splicing.
 This study will identify novel E1B55K/E4orf6 substrates that can link the function of the viral ligase to viral
RNA processing. Further, novel mechanisms by which viruses use ubiquitination to manipulate cellular
processes will be revealed. Accomplishing the proposed aims will provide me training in experimental methods
to study host-pathogen interactions and strengthen my b...

## Key facts

- **NIH application ID:** 9995373
- **Project number:** 5F32AI147587-02
- **Recipient organization:** CHILDREN'S HOSP OF PHILADELPHIA
- **Principal Investigator:** Joseph M Dybas
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $69,306
- **Award type:** 5
- **Project period:** 2019-07-01 → 2021-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9995373

## Citation

> US National Institutes of Health, RePORTER application 9995373, Investigating the role of ubiquitination in regulating viral RNA processing during Adenovirus infection (5F32AI147587-02). Retrieved via AI Analytics 2026-06-01 from https://api.ai-analytics.org/grant/nih/9995373. Licensed CC0.

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