# Defining the Structural Mechanisms of RNP Complexes that Regulate Enterovirus Translation

> **NIH NIH R01** · CASE WESTERN RESERVE UNIVERSITY · 2021 · $359,893

## Abstract

Project abstract: Enteroviruses (EVs) coordinate protein synthesis and genome replication through their
5'UTR, which is predicted to fold into six stem loops. Stem loop (SL) I facilitates viral genome replication; SLII-
VI function as the basic IRES unit for cap-independent translation. Several host RNA binding proteins (referred
to as ITAFs), are recruited to the IRES for efficient viral protein synthesis. The current dogma supports a model
wherein ITAFs either stabilize or destabilize IRES structure in a conformation that controls ribosome entry. The
fundamental knowledge gap is an understanding of mechanisms by which ITAFs functionally interact with the
5'UTR to organize IRES structure. This knowledge is critical to reveal underlying mechanisms by which EVs
redirect host factors to maintain infection. The long-term goal is to better understand the molecular mecha-
nisms by which EVs subvert host factors to regulate viral gene expression and replication. The overall objec-
tive of this proposal is to illuminate how ITAFs functionally interact with the viral IRES to control translation.
EV71 and the ITAFs hnRNP A1 and AUF1 serve as excellent models as they bind the same IRES domain SLII
to antagonistically fine-tune EV71 translation levels. Moreover, vsRNA1, a virus-derived, small RNA produced
by Dicer cleavage of the SLII IRES region, further represses EV71 translation. Our central hypothesis is that
conserved viral RNA elements fine-tune EV71 translation levels by assembling unique and antagonistic ribo-
nucleoprotein (RNP) complexes, and vsRNA1 compete these interactions to permit more stringent control. The
rationale for this research is that ITAF-IRES interactions are central to the synthesis of every EV71 protein and
its replication. This new knowledge will thus prove applicable to similar EVs as well. Strong preliminary data
lead to three specific aims: (1) Determine the structures of IRES elements that contribute to viral replication; (2)
reveal the detailed molecular interactions of antagonistic ITAFs that coordinate viral translation; and (3) identify
mechanisms by which viral small RNAs inhibit translation. For Aim1, phylogenetics, chemical probing, NMR,
SAXS, and cellular assays will define IRES structural elements that contribute to EV71 translation. For Aim 2,
structural, biophysical, and virological assays will reveal protein and RNA conformational changes, and func-
tional changes, upon binding of hnRNP A1 and AUF1 to the IRES SLII region, which is critical to translational
control. For Aim 3, structural, biochemical, and virological assays will reveal the structural and functional ef-
fects of vsRNA1 on antagonistic hnRNP A1- and AUF1-RNPs. The proposal is innovative by employing an in-
tegrated program combining structural biochemistry, biophysics, and virological studies that promise to provide
significant breakthroughs to better understand viral-host interactions that contribute to EV71 pathogenesis. The
research is significa...

## Key facts

- **NIH application ID:** 10092187
- **Project number:** 5R01GM126833-04
- **Recipient organization:** CASE WESTERN RESERVE UNIVERSITY
- **Principal Investigator:** Gary A. Brewer
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $359,893
- **Award type:** 5
- **Project period:** 2018-01-01 → 2022-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10092187

## Citation

> US National Institutes of Health, RePORTER application 10092187, Defining the Structural Mechanisms of RNP Complexes that Regulate Enterovirus Translation (5R01GM126833-04). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10092187. Licensed CC0.

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