Characterization of the Plasmodium falciparum and P. berghei glycerol 3‐phosphate acyltransferase involved in FASII fatty acid utilization in the malaria parasite apicoplast

Abstract

SummaryMalaria parasites can synthesize fatty acids via a type II fatty acid synthesis (FASII) pathway located in their apicoplast. The FASII pathway has been pursued as an anti‐malarial drug target, but surprisingly little is known about its role in lipid metabolism. Here we characterize the apicoplast glycerol 3‐phosphate acyltransferase that acts immediately downstream of FASII in human (Plasmodium falciparum) and rodent (Plasmodium berghei) malaria parasites and investigate how this enzyme contributes to incorporating FASII fatty acids into precursors for membrane lipid synthesis. Apicoplast targeting of the P. falciparum and P. berghei enzymes are confirmed by fusion of the N‐terminal targeting sequence to GFP and 3′ tagging of the full length protein. Activity of the P. falciparum enzyme is demonstrated by complementation in mutant bacteria, and critical residues in the putative active site identified by site‐directed mutagenesis. Genetic disruption of the P. falciparum enzyme demonstrates it is dispensable in blood stage parasites, even in conditions known to induce FASII activity. Disruption of the P. berghei enzyme demonstrates it is dispensable in blood and mosquito stage parasites, and only essential for development in the late liver stage, consistent with the requirement for FASII in rodent malaria models. However, the P. berghei mutant liver stage phenotype is found to only partially phenocopy loss of FASII, suggesting newly made fatty acids can take multiple pathways out of the apicoplast and so giving new insight into the role of FASII and apicoplast glycerol 3‐phosphate acyltransferase in malaria parasites.

Validation of Putative Apicoplast-Targeting Drugs Using a Chemical Supplementation Assay in Cultured Human Malaria Parasites

“…5). This is entirely consistent with the asexual blood stage essentiality of isoprenoid precursor synthesis (37) and the dispensability of apicoplast fatty acid biosynthesis at this life stage (31,(115)(116)(117), and it definitively shows that apicoplast fatty acid synthesis is not a drug target during the parasite asexual blood stages. IPP rescue assays thus present an efficient means of screening new compounds and will hopefully eliminate the misplaced effort in drug development that has occurred previously.…”

Global genetic diversity of var2csa in Plasmodium falciparum with implications for malaria in pregnancy and vaccine development

“…Raw sequencing data from Illumina data was available for previously published P. falciparum strains (3D7, HB3, D10, 7G8 and GB4) 29 , 30 and isolates from East Africa (Kenya (n = 38), Malawi (353), Tanzania (63), Uganda (12), Madagascar (18)), West Africa (Burkina Faso (48), Gambia (63), Ghana (443), Guinea (116), Mali (55), Nigeria (6), Cameroon (127)), Central Africa (Democratic Republic of Congo (DRC) (232)), South America (Colombia (15), Peru (9), Brazil (3)), South Asia (Bangladesh (53)) and South East Asia and Oceania (Cambodia (649), Laos (112), Myanmar (134), Papua New Guinea (26), Thailand (326), Vietnam (199)) 31 . Public accession numbers for raw sequence data analysed are contained in SRA studies ERP000190 and ERP000199, as well as being accessible from the Pf3k project website ( https://www.malariagen.net/projects/pf3k ).…”

Plasma metabolomics reveals membrane lipids, aspartate/asparagine and nucleotide metabolism pathway differences associated with chloroquine resistance in Plasmodium vivax malaria

“…Metabolomics in malaria, namely targeted metabolomics, was applied almost exclusively to identify P . falciparum stage-specific changes in metabolic pathways involved in parasite differentiation and invasion in order to better inform drug discovery and design [ 31 – 35 ] or to predict disease severity [ 36 – 39 ]. In this context, metabolomics has been used to gain understanding of the intraerythrocytic development cycle of P .…”