# Regulation of Rotavirus Replication

> **NIH NIH R01** · BAYLOR COLLEGE OF MEDICINE · 2021 · $530,667

## Abstract

Project Summary
Our long-term goal is to understand how rotavirus (RV) exploits cellular pathways such as autophagy
membranes, calcium homeostasis, and lipid droplet (LD) formation to enhance their replication and cause
disease. RVs remain significant human pathogens in spite of the introduction of vaccines. Several aspects of RV
replication are unique yet broadly relevant to other viruses, such as cytoplasmic organelles (viroplasms, VI)
formed by both viral and cellular proteins and LDs that form a physical platform for efficient viral replication and
maturation. LDs are dynamic, multi-functional intracellular organelles involved in lipid storage and metabolism
as well as in signal transduction, membrane trafficking and modulation of immune and inflammatory responses.
LDs play essential roles in several viral and intracellular bacterial infections and are important in many aspects
of health and disease (metabolism, diabetes, obesity, heart disease). However, mechanistic information of the
interplay between lipid accumulation and these pathogens, and disease is far from complete. Our proposed
studies on LDs and VIs build on our recent work. While the viral proteins NSP2 and NSP5 are known to be
required for VI formation, the molecular mechanisms of how these two proteins associate with each other as well
as with other viral and cellular proteins and LD components to form VI/LDs remain to be elucidated. We
discovered two forms of NSP2 that interact with different isoforms of NSP5: a dispersed (dNSP2) form interacts
with hypo-phosphorylated NSP5 and a previously recognized VI (vNSP2) form interacts with hyper-
phosphorylated NSP5. We elucidated a novel phosphorylation-dependent mechanism for VI formation, in which
the ubiquitous, constitutively active cellular protein kinase CK1α partially controls the assembly of RV VIs by
phosphorylating NSP2 to trigger NSP2 octamer-octamer lattice formation. We also discovered that NSP2 is an
autokinase and predict that NSP2 may phosphorylate other viral or cellular proteins for VI assembly and RV
replication. We hypothesize that interactions of RV and cellular proteins in specialized microdomains of the
endoplasmic reticulum nucleate and induce VI/LDs essential for virus replication, affect the composition of the
LD-associated proteins and result in previously unrecognized mechanisms of RV-induced pathogenesis. We
propose experiments to answer three questions. (1) How do NSP4, NSP2 and specialized microdomains in the
ER lead to nucleation of VI/LDs? (2) How does phosphorylation orchestrate VI formation and the conversion of
dNSP2 to vNSP2 to initiate VI/LD formation and subsequent VI/LD maturation? (3) How does DGAT1
degradation lead to LD formation and what are the specific roles of PLIN1 and PLIN3 LDs in RV infection and
pathogenesis? These studies are significant because viral perturbations of host signaling and metabolic
pathways that involve LDs are critical for multiple pathogens. Because RVs replicate in...

## Key facts

- **NIH application ID:** 10137172
- **Project number:** 5R01AI080656-12
- **Recipient organization:** BAYLOR COLLEGE OF MEDICINE
- **Principal Investigator:** Sue Ellen Crawford
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $530,667
- **Award type:** 5
- **Project period:** 2009-08-11 → 2025-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10137172

## Citation

> US National Institutes of Health, RePORTER application 10137172, Regulation of Rotavirus Replication (5R01AI080656-12). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10137172. Licensed CC0.

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