Comprehensive characterisation of purine and pyrimidine transport activities in Trichomonas vaginalis and functional cloning of a trichomonad nucleoside transporter

Natto, M. J., Miyamoto, Y., Munday, J. C. , AlSiari, T. A., Al-Salabi, M. I., Quashie, N. B., Eze, A. A., Eckmann, L. and De Koning, H. P. (2021) Comprehensive characterisation of purine and pyrimidine transport activities in Trichomonas vaginalis and functional cloning of a trichomonad nucleoside transporter. Molecular Microbiology, 116(6), pp. 1489-1511. (doi: 10.1111/mmi.14840) (PMID:34738285)

Abstract

Trichomoniasis is a common and widespread sexually-transmitted infection, caused by the protozoan parasite Trichomonas vaginalis. T. vaginalis lacks the biosynthetic pathways for purines and pyrimidines, making nucleoside metabolism a drug target. Here we report the first comprehensive investigation into purine and pyrimidine uptake by T. vaginalis. Multiple carriers were identified and characterised with regard to substrate selectivity and affinity. For nucleobases, a high affinity adenine transporter, a possible guanine transporter and a low affinity uracil transporter were found. Nucleoside transporters included two high affinity adenosine/guanosine/uridine/cytidine transporters distinguished by different affinities to inosine, a lower affinity adenosine transporter, and a thymidine transporter. Nine Equilibrative Nucleoside Transporter (ENT) genes were identified in the T. vaginalis genome. All were expressed equally in metronidazole-resistant and -sensitive strains. Only TvagENT2 was significantly upregulated in the presence of extracellular purines; expression was not affected by co-culture with human cervical epithelial cells. All TvagENTs were cloned and separately expressed in Trypanosoma brucei. We identified the main broad specificity nucleoside carrier, with high affinity for uridine and cytidine as well as purine nucleosides including inosine, as TvagENT3. The in-depth characterisation of purine and pyrimidine transporters provides a critical foundation for the development of new anti-trichomonal nucleoside analogues.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Munday, Dr Jane and De Koning, Professor Harry and Al-Salabi, Dr Mohammed and Natto, Dr Manal and Quashie, Mr Neils and ALSiari, Miss Tahani
• Authors: Natto, M. J., Miyamoto, Y., Munday, J. C., AlSiari, T. A., Al-Salabi, M. I., Quashie, N. B., Eze, A. A., Eckmann, L., and De Koning, H. P.
• College/School: College of Medical Veterinary and Life Sciences > School of Infection & Immunity
• Journal Name: Molecular Microbiology
• Publisher: Wiley
• ISSN: 0950-382X
• ISSN (Online): 1365-2958
• Published Online: 04 November 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Molecular Microbiology 116(6): 1489-1511
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
160073		Drug resistance in African trypanosomes	Harry De Koning	Medical Research Council (MRC)	G0701258	III - Parasitology