Plasmodium yoelii Vitamin B5 Pantothenate Transporter Candidate is Essential for Parasite Transmission to the Mosquito

Abstract

In nearly all non-photosynthetic cells, pantothenate (vitamin B5) transport and utilization are prerequisites for the synthesis of the universal essential cofactor Coenzyme A (CoA). Early studies showed that human malaria parasites rely on the uptake of pantothenate across the parasite plasma membrane for survival within erythrocytes. Recently, a P. falciparum candidate pantothenate transporter (PAT) was characterized by functional complementation in yeast. These studies revealed that PfPAT mediated survival of yeast cells in low pantothenate concentrations and restored sensitivity of yeast cells lacking pantothenate uptake to fenpropimorph. In addition, PfPAT was refractory to deletion in P. falciparum in vitro, but nothing is known about the in vivo functions of PAT in Plasmodium life cycle stages. Herein, we used gene-targeting techniques to delete PAT in Plasmodium yoelii. Parasites lacking PAT displayed normal asexual and sexual blood stage development compared to wild-type (WT) and WT-like p230p(-) parasites. However, progression from the ookinete to the oocyst stage and sporozoite formation were completely abolished in pat(-) parasites. These studies provide the first evidence for an essential role of a candidate pantothenate transport in malaria transmission to Anopheles mosquitoes. This will set the stage for the development of PAT inhibitors against multiple parasite life cycle stages.

Genetic Characterization of Plasmodium Putative Pantothenate Kinase Genes Reveals Their Essential Role in Malaria Parasite Transmission to the Mosquito

“…The same targeting vector was used to disrupt the dispensable PyP230p locus as a control for the transfection vector and procedures. All vectors were linearized and transfected in the same transfection experiment with PyPAT , which was previously published 22 . Transgenic parasites were cloned and analyzed by PCR to confirm the genetic replacement events and the deletion of PyPanK1 ( Fig.…”

“…Earlier studies in P. lophurae have shown that this avian parasite can scavenge host CoA for survival in ducks erythrocytes 6 21 . Similarly, genetic studies in the murine malaria parasite P. yoelii have shown that parasites lacking a candidate pantothenic acid transporter undergo normal asexual development in mouse erythrocytes, suggesting the presence of an alternative route for CoA biosynthesis in this parasite or an alternative pantothenate secondary transporter 22 .…”

Fatty acid metabolism in the Plasmodium apicoplast: Drugs, doubts and knockouts

“…Although a triose phosphate shuttle has been identified as a second source of reducing equivalents in the T. gondii apicoplast [117], there is no evidence for such a pathway in Plasmodium [21,26,112,185], leaving the balance of reducing power in the parasite organelle in apparent deficit. The source of the biotin, thiamine pyrophosphate and CoA required by ACC, PDH and ACPS are also somewhat unclear, with enzymes involved in the synthesis or scavenging of these cofactors identified in Plasmodium [26,187,188], but little research to date addressing their provision to the apicoplast [189][190][191][192][193]. To gain a more wholistic understanding of FASII, characterization of its remaining enzymes and elucidation of these underlying pathways is a necessity.…”

The s48/45 six-cysteine proteins: mediators of interaction throughout the Plasmodium life cycle

“…Deletion mutants in P. berghei and P. yoelii have shown no effect on the parasite life cycle and in fact the P230p locus has even been used as a reporter insertion site (Janse et al, 2006; van Dijk et al, 2010; Lin et al, 2011; Hart et al, 2014). Functional redundancy with Pfs230 has been ruled out since the expression pattern of these proteins is different and no compensating upregulation was observed for Pfs230p in a ΔPfs230 mutant (Eksi and Williamson, 2002; Eksi et al, 2006).…”