# Mechanistic regulation of ammonia metabolism in Aedes aegypti mosquitoes

> **NIH NIH R01** · TULANE UNIVERSITY OF LOUISIANA · 2021 · $380,276

## Abstract

PROJECT SUMMARY
Aedes aegypti females have evolved efficient metabolic pathways for managing the high ammonia
concentrations that are released during a blood meal's digestion. Carbon (C) atoms from glucose are required
for clearance of ammonia and excess nitrogen (N) disposal through the interplay of multiple pathways,
including glycolysis, and ammonia fixation, assimilation and excretion pathways. What remains unknown is
how these intersecting metabolic pathways are regulated. The long-term goal is to identify the biochemical and
molecular bases underlying the regulation of N and C metabolism in Ae. aegypti, so that novel metabolism-
based strategies for mosquito control can be developed as a way to improve public health and quality of life.
The overall objective for this application is to identify the mechanisms involved in the regulation of polyamines
and glucose/ammonia metabolism. The central hypothesis is that the proper disposition of N waste is
controlled by uric acid and polyamine fluxes, and by proteins involved in the last step of glycolysis. The
rationale for the proposed research is that the identification of regulatory mechanisms will provide new
opportunities for the subsequent identification of targets for the design of innovative strategies to mosquito
control. Guided by strong preliminary data, the central hypothesis will be tested by pursuing two specific aims:
1) Determine the metabolic flux of polyamines and the mechanisms of its regulation in blood-fed mosquitoes;
2) Identify mechanisms of regulation of both glucose and ammonia metabolism in mosquitoes. Under the first
aim, stable isotopically labeled compounds and advanced LC/MS methods, western blots, qRT-PCR, chemical
inhibitors and reverse genetics techniques will be used. In the second aim, standard techniques for gene
cloning, protein purification, kinetic characterization, crystallization and structure determination will be
performed. Further, immunoprecipitation, inmunofluorence, RNA interference, and metabolomics analysis will
be performed. This approach is innovative because it combines classical and state-of-the-art techniques (i) to
monitor metabolite flux at atomic level without sample derivatization and (ii) to identify regulatory mechanisms
of polyamine, glucose/ammonia metabolism at different levels including transcriptional and post-translational
levels. The proposed research is significant because it is expected to fill gaps in current understanding of how
female mosquitoes maintain N and C metabolism and regulate the proper disposition of N waste upon a blood
meal without which ammonia levels could reach lethal concentrations. Thus, these results are expected to
uncover mosquito-specific regulatory mechanisms under high demands of ammonia detoxification. As such, a
much-improved fundamental understanding of the biochemical and molecular bases underlying the N and C
metabolism in mosquitoes can be anticipated. It is also expected that what can be learned in...

## Key facts

- **NIH application ID:** 10159210
- **Project number:** 5R01AI146199-03
- **Recipient organization:** TULANE UNIVERSITY OF LOUISIANA
- **Principal Investigator:** Patricia Yolanda Scaraffia
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $380,276
- **Award type:** 5
- **Project period:** 2019-06-06 → 2025-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10159210

## Citation

> US National Institutes of Health, RePORTER application 10159210, Mechanistic regulation of ammonia metabolism in Aedes aegypti mosquitoes (5R01AI146199-03). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10159210. Licensed CC0.

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