# Cellular Targets of the BKPyV miRNA

> **NIH NIH R21** · UNIVERSITY OF MICHIGAN AT ANN ARBOR · 2020 · $234,000

## Abstract

Viruses encode multifunctional non-structural proteins in order to accommodate as much coding
potential as possible into their relatively small genomes. Many of these proteins often interact
with multiple host cell factors to manipulate the host environment to make it more conducive to
virus replication and to help the virus evade the immune system, for example. Various viruses
also express non-coding RNA molecules such as microRNAs (miRNAs), but the roles of these
miRNAs are much less well understood. It stands to reason that, as is the case for non-
structural proteins, viruses would evolve to maximize the utility of the miRNAs. BK polyomavirus
(BKPyV) is a small DNA virus that is ubiquitous in the human population. In healthy individuals,
it persists in the urinary tract without causing obvious disease, but in transplant patients,
uncontrolled virus replication has serious outcomes. BKPyV encodes two miRNAs from a single
pre-miRNA precursor. These miRNAs downregulate expression of the viral tumor (T) antigens,
multifunctional proteins that facilitate virus replication by stimulating S phase entry and recruiting
the host DNA synthetic machinery to the viral chromosome. These miRNAs do not affect
replication of disease-associated genetic BKPyV variants, but severely limit replication of the
archetype, or wild type, virus that circulates through the population and establishes a persistent
infection. In this proposal, we will test the hypothesis that like their protein counterparts, the
miRNAs are multifunctional macromolecules that also target host factors to facilitate virus
infection. The two aims are to identify host targets and begin to assess the role of those targets
in BKPyV infection.

## Key facts

- **NIH application ID:** 9975095
- **Project number:** 5R21AI147155-02
- **Recipient organization:** UNIVERSITY OF MICHIGAN AT ANN ARBOR
- **Principal Investigator:** MICHAEL J. IMPERIALE
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $234,000
- **Award type:** 5
- **Project period:** 2019-07-09 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9975095

## Citation

> US National Institutes of Health, RePORTER application 9975095, Cellular Targets of the BKPyV miRNA (5R21AI147155-02). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/9975095. Licensed CC0.

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