# Polyamine Transport in Schistosomes

> **NIH NIH R21** · TUFTS UNIVERSITY BOSTON · 2022 · $247,500

## Abstract

Summary:
Schistosomes are intravascular parasitic worms that cause the debilitating disease schistosomiasis which
affects > 200 million people in > 70 countries. In this proposal, we focus on polyamine metabolism in
schistosomes. Polyamines are ubiquitous organic compounds that play multiple vital roles in cellular
physiology. An exhaustive search of genome databases reveals that schistosomes lack all the de novo
polyamine biosynthetic enzymes. This makes schistosomes the only known metazoans that are auxotrophic
for polyamines. How these worms acquire these essential metabolites is not known. The P5-type ATPase,
CATP5, identified in the nematode C. elegans has been shown to function as a polyamine transporter. Here
we describe our newly identified CATP5 homolog in S. mansoni - SmCATP5 - that is found in the schistosome
tegument (skin) where, we hypothesize, it functions to import polyamines from host blood. Knockdown of
SmCATP5 expression using RNAi debilitates the worms in culture, while polyamine supplementation enhances
worm viability. In this proposal, we aim to characterize the functionality, specificity and kinetics of polyamine
transport in schistosomes. We will examine SmCATP5 function using a heterologous expression system in a
polyamine-uptake-deficient cell line (CHO-MG) as well as directly in schistosome parasites. This work is
designed to reveal the physiological function of SmCATP5 and should yield significant new information on the
molecular mechanisms used by schistosomes to obtain vital nutrients (polyamines). Since schistosomes are
completely dependent on their hosts as a source of polyamines, blocking SmCATP5 function should debilitate
the worms and could form the basis of a new anti-schistosome therapy – the long-term aim of this work.

## Key facts

- **NIH application ID:** 10434131
- **Project number:** 5R21AI163307-02
- **Recipient organization:** TUFTS UNIVERSITY BOSTON
- **Principal Investigator:** Akram Da'Darah
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $247,500
- **Award type:** 5
- **Project period:** 2021-06-17 → 2024-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10434131

## Citation

> US National Institutes of Health, RePORTER application 10434131, Polyamine Transport in Schistosomes (5R21AI163307-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10434131. Licensed CC0.

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