Mutant/mutation
The mutant lacks expression of pantothenate transporter (PAT) and expresses GFP under the control of the strong and constitutive hsp70 promoter.

Protein (function)
Pantothenic acid (or vitamin B5, or when ionized as pantothenate) is a precursor of coenzyme A (CoA), which is an essential enzyme cofactor in all living organisms. CoA plays important roles in cellular metabolism and fatty acid biosynthesis. Pantothenate acquisition from extracellular sources has been shown to be essential in nearly all non-photosynthetic cells for CoA biosynthesis. Culture media lacking pantothenic acid do not allow growth of P. falciparum. Supplementation of this vitamin B5-free medium with pantothenic acid alone was sufficient to restore normal parasite growth, suggesting that pantothenic acid is an essential vitamin transported by the parasite from host plasma and is absolutely required for parasite intraerythrocytic development. Since pantothenic acid requires a specialized transporter to move across cellular membranes, the transport of this essential precursor into P. falciparum-infected erythrocytes and its subsequent metabolism into CoA are therefore essential for this parasite’s survival. All CoA biosynthesis genes have been identified in the Plasmodium genomes except the pantothenate transporter.
A conserved putative transporter gene with multiple transmembrane domains have been functionally characterized as a candidate pantothenate transporter (PAT) in P.  falciparum. PfPAT localized to the parasite plasma membrane of P. falciparum and its expression in a fen2D yeast mutant (lacking the only pantothenate transporter Fen2p) restored growth on low pantothenate concentrations and restored sensitivity to the antifungal drug, fenpropimorph, which is primarily transported into yeast cells via the Fen2 permease. Moreover, genetic studies in P. falciparum indicated that PfPAT gene is not amenable to targeted deletion by classical genetic methods and down-regulation of its expression using morpholino-based oligonucleotides resulted in parasite death. Together these data indicated that PfPAT might function as the primary pantothenate transporter of P. falciparum and its transport activity could be essential for BS development.

Phenotype
Blood stage development, gametocyte and ookinete production were similar to that of wild type parasites. No (mature) oocysts are formed. No sporozoites are formed indicating an essential role of PAT in the transition of mature ookinetes into (mature) oocysts.

Additional information

Other mutants