# REGULATION OF ALPHAVIRUS TRANSCRIPTION

> **NIH NIH R01** · UNIVERSITY OF TOLEDO HEALTH SCI CAMPUS · 1989 · $129,385

## Abstract

Alphaviruses are an important cause of mosquito-borne encephalitis.  Our
overall aim is to determine the mechanism of alphavirus transcription and
to understand how the synthesis of viral minus and plus strand RNA is
regulated.  The viral encoded nonstructural proteins of the alphaviruses
Sindbis virus (SIN) and Semliki Forest virus (SFV) which initiate viral
replication by transcribing the infecting viral plus-strand genome RNA into
a complementary minus-strand RNA will be characterized as to their function
in viral replication.  Temperature sensitive mutants of SIN and SFV and
their revertants that we have characterized previously will be used to
identify the functions of the viral proteins that are required for
minus-strand RNA synthesis and to determine if the regulation of
minus-strand RNA synthesis involves cis-acting or trans-acting viral
functions.  We will study defective interferring particles (DIs) of SIN HR
to determine whether nondefective virus is capable of shutting off the
synthesis of the minus-strand template for the DI RNA.  We will sequence,
by the method of primer extension using reverse transcriptase and
dideoxynucleotides with purified viral genomes as templates, the genes
encoding the third and fourth nonstructural proteins of SIN HR, ts6, ts11
and ts24 and revertants of these mutants.  Our previous research leads us
to suspect that the third or the fourth nonstructural protein of the
alphavirus genome is encoded by the B or the F cistron.  We will continue
to develop an in vitro assay to characterize alphavirus transcription,
particularly, minus strand synthesis using viral RNA produced in vitro from
cloned viral RNA.  We plan to clone the nonstructural genes and required
flanking sequences of both SIN HR and selected temperature sensitive
mutants of SIN HR into Riboprobe Gemini plasmid vectors in order to analyze
the sequence requirements for synthesis and regulation of alphavirus
plus-strand and minus-strand RNA synthesis.  Lastly, we will identify and
characterize the viral encoded protease that processes the polyprotein
precursor to the viral nonstructural proteins and that appears to be
temperature sensitive in SIN HR ts17.

## Key facts

- **NIH application ID:** 3126024
- **Project number:** 5R01AI015123-12
- **Recipient organization:** UNIVERSITY OF TOLEDO HEALTH SCI CAMPUS
- **SAM.gov UEI:** M9ACC5DQCNL6
- **Principal Investigator:** DOROTHEA L SAWICKI
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 1989
- **Award amount:** $129,385
- **Award type:** 5
- **Project period:** 1978-09-01 → 1991-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/3126024

## Citation

> US National Institutes of Health, RePORTER application 3126024, REGULATION OF ALPHAVIRUS TRANSCRIPTION (5R01AI015123-12). Retrieved via MORVS 2026-10-25 from https://api.morvs.ai/grant/nih/3126024. Licensed CC0.

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