Characteristics of Plasmodium vivax apicomplexan amino acid transporter 8 (PvApiAT8) in the cationic amino acid transport

Abstract Plasmodium vivax is the most widespread malaria parasite affecting humans, and its eradication is challenging due to the spread of drug-resistant parasites and their ability to remain in liver as a dormant stage. These parasites invade and multiply extensively within hepatocytes and erythro...

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Main Authors: Wang-Jong Lee, Ernest Mazigo, Jin-Hee Han, Seok Ho Cha
Format: Article
Language:English
Published: Nature Portfolio 2025-02-01
Series:Scientific Reports
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Online Access:https://doi.org/10.1038/s41598-025-88746-2
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author Wang-Jong Lee
Ernest Mazigo
Jin-Hee Han
Seok Ho Cha
author_facet Wang-Jong Lee
Ernest Mazigo
Jin-Hee Han
Seok Ho Cha
author_sort Wang-Jong Lee
collection DOAJ
description Abstract Plasmodium vivax is the most widespread malaria parasite affecting humans, and its eradication is challenging due to the spread of drug-resistant parasites and their ability to remain in liver as a dormant stage. These parasites invade and multiply extensively within hepatocytes and erythrocytes in the host, relying on nutrient acquisition for their growth and replication. A promising new treatment aimed at targeting P. vivax involves blocking cationic amino acid uptake, which is a biological source of nutrients for the parasite. Novel Putative Transporter 1 (NPT1), identified as a cationic amino acid transporter in Apicomplexan, has a homologue in Plasmodium species known as apicomplexan amino acid transporter 8 (ApiAT8). This study focuses on P. vivax ApiAT8 to understand its precise role. PvApiAT8 was expressed in Xenopus laevis oocytes and shown to selectively uptake cationic amino acids. The uptake activity of [3H] L-arginine was shown to depend on PvApiAT8 expression time and substrate incubation time. PvApiAT8 was sodium-independent and functioned at pH levels between 6.5 and 8.5, with no efflux activity observed. Kinetic analysis showed saturable uptake for L-arginine consistent with Michaelis-Menten kinetics, with a Km of 1.5 ± 0.3 µM and a Vmax of 25.0 ± 4.8 pmol/oocyte/hr. Inhibition assays further confirmed its selectivity for cationic amino acids such as L-arginine, L-lysine, L-histidine, and L-ornithine. Sequence and structural analyses revealed a conserved binding pocket for cationic amino acids in Plasmodium species, distinct from that in Toxoplasma gondii NPT1. These findings highlight the potential of targeting PvApiAT8 in developing new treatments for P. vivax malaria.
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spelling doaj-art-4dd30aed5ba2431c85955535dc3a78632025-02-09T12:35:27ZengNature PortfolioScientific Reports2045-23222025-02-0115111010.1038/s41598-025-88746-2Characteristics of Plasmodium vivax apicomplexan amino acid transporter 8 (PvApiAT8) in the cationic amino acid transportWang-Jong Lee0Ernest Mazigo1Jin-Hee Han2Seok Ho Cha3Department of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National UniversityDepartment of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National UniversityDepartment of Medical Environmental Biology and Tropical Medicine, School of Medicine, Kangwon National UniversityDepartment of Parasitology and Tropical Medicine, School of Medicine, Inha UniversityAbstract Plasmodium vivax is the most widespread malaria parasite affecting humans, and its eradication is challenging due to the spread of drug-resistant parasites and their ability to remain in liver as a dormant stage. These parasites invade and multiply extensively within hepatocytes and erythrocytes in the host, relying on nutrient acquisition for their growth and replication. A promising new treatment aimed at targeting P. vivax involves blocking cationic amino acid uptake, which is a biological source of nutrients for the parasite. Novel Putative Transporter 1 (NPT1), identified as a cationic amino acid transporter in Apicomplexan, has a homologue in Plasmodium species known as apicomplexan amino acid transporter 8 (ApiAT8). This study focuses on P. vivax ApiAT8 to understand its precise role. PvApiAT8 was expressed in Xenopus laevis oocytes and shown to selectively uptake cationic amino acids. The uptake activity of [3H] L-arginine was shown to depend on PvApiAT8 expression time and substrate incubation time. PvApiAT8 was sodium-independent and functioned at pH levels between 6.5 and 8.5, with no efflux activity observed. Kinetic analysis showed saturable uptake for L-arginine consistent with Michaelis-Menten kinetics, with a Km of 1.5 ± 0.3 µM and a Vmax of 25.0 ± 4.8 pmol/oocyte/hr. Inhibition assays further confirmed its selectivity for cationic amino acids such as L-arginine, L-lysine, L-histidine, and L-ornithine. Sequence and structural analyses revealed a conserved binding pocket for cationic amino acids in Plasmodium species, distinct from that in Toxoplasma gondii NPT1. These findings highlight the potential of targeting PvApiAT8 in developing new treatments for P. vivax malaria.https://doi.org/10.1038/s41598-025-88746-2Plasmodium vivaxCationic amino acid transporterXenopus laevis oocyteArginineLysineHistidine
spellingShingle Wang-Jong Lee
Ernest Mazigo
Jin-Hee Han
Seok Ho Cha
Characteristics of Plasmodium vivax apicomplexan amino acid transporter 8 (PvApiAT8) in the cationic amino acid transport
Scientific Reports
Plasmodium vivax
Cationic amino acid transporter
Xenopus laevis oocyte
Arginine
Lysine
Histidine
title Characteristics of Plasmodium vivax apicomplexan amino acid transporter 8 (PvApiAT8) in the cationic amino acid transport
title_full Characteristics of Plasmodium vivax apicomplexan amino acid transporter 8 (PvApiAT8) in the cationic amino acid transport
title_fullStr Characteristics of Plasmodium vivax apicomplexan amino acid transporter 8 (PvApiAT8) in the cationic amino acid transport
title_full_unstemmed Characteristics of Plasmodium vivax apicomplexan amino acid transporter 8 (PvApiAT8) in the cationic amino acid transport
title_short Characteristics of Plasmodium vivax apicomplexan amino acid transporter 8 (PvApiAT8) in the cationic amino acid transport
title_sort characteristics of plasmodium vivax apicomplexan amino acid transporter 8 pvapiat8 in the cationic amino acid transport
topic Plasmodium vivax
Cationic amino acid transporter
Xenopus laevis oocyte
Arginine
Lysine
Histidine
url https://doi.org/10.1038/s41598-025-88746-2
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