Mutations in the pantothenate kinase of Plasmodium falciparum confer diverse sensitivity profiles to antiplasmodial pantothenate analogues

Erick T Tjhin; Christina Spry; Alan L Sewell; Annabelle Hoegl; Leanne Barnard; Anna E Sexton; Ghizal Siddiqui; Vanessa M Howieson; Alexander G Maier; Darren J Creek; Erick Strauss; Rodolfo Marquez; Karine Auclair; Kevin J Saliba

doi:10.1371/journal.ppat.1006918

Mutations in the pantothenate kinase of Plasmodium falciparum confer diverse sensitivity profiles to antiplasmodial pantothenate analogues

PLoS Pathog. 2018 Apr 3;14(4):e1006918. doi: 10.1371/journal.ppat.1006918. eCollection 2018 Apr.

Authors

Affiliations

¹ Research School of Biology, The Australian National University, Canberra, Australia.
² Department of Chemistry, University of Glasgow, Glasgow, United Kingdom.
³ Department of Chemistry, McGill University, Montreal, Quebec, Canada.
⁴ Department of Biochemistry, Stellenbosch University, Matieland, South Africa.
⁵ Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Australia.
⁶ Department of Chemistry, Xi'an Jiaotong-Liverpool University, Suzhou, China.
⁷ Medical School, The Australian National University, Canberra, Australia.

Abstract

The malaria-causing blood stage of Plasmodium falciparum requires extracellular pantothenate for proliferation. The parasite converts pantothenate into coenzyme A (CoA) via five enzymes, the first being a pantothenate kinase (PfPanK). Multiple antiplasmodial pantothenate analogues, including pantothenol and CJ-15,801, kill the parasite by targeting CoA biosynthesis/utilisation. Their mechanism of action, however, remains unknown. Here, we show that parasites pressured with pantothenol or CJ-15,801 become resistant to these analogues. Whole-genome sequencing revealed mutations in one of two putative PanK genes (Pfpank1) in each resistant line. These mutations significantly alter PfPanK activity, with two conferring a fitness cost, consistent with Pfpank1 coding for a functional PanK that is essential for normal growth. The mutants exhibit a different sensitivity profile to recently-described, potent, antiplasmodial pantothenate analogues, with one line being hypersensitive. We provide evidence consistent with different pantothenate analogue classes having different mechanisms of action: some inhibit CoA biosynthesis while others inhibit CoA-utilising enzymes.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Antimalarials / pharmacology*
Coenzyme A / biosynthesis
Drug Resistance*
Erythrocytes / parasitology
Malaria / drug therapy*
Malaria / parasitology
Mutation*
Pantothenic Acid / analogs & derivatives*
Pantothenic Acid / pharmacology
Parasitic Sensitivity Tests
Phosphorylation
Phosphotransferases (Alcohol Group Acceptor) / genetics*
Plasmodium falciparum / drug effects*
Protozoan Proteins / genetics

Substances

Antimalarials
CJ-15,801
Protozoan Proteins
Pantothenic Acid
Phosphotransferases (Alcohol Group Acceptor)
pantothenate kinase
Coenzyme A

Grants and funding

Part of this work was funded by a grant from the National Health and Medical Research Council (NHMRC) of Australia to KJS and KA. (APP1129843), and a grant from the Canadian Institute of Health Research (CIHR) to KA. ETT was supported by a Research Training Program scholarship from the Australian Government. CS was funded by an NHMRC Overseas Biomedical Fellowship (1016357). CIHR provided a graduate scholarship to AH. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.