The Apicoplast: A Review of the Derived Plastid of Apicomplexan Parasites

Abstract

The apicoplast is a plastid organelle, homologous to chloroplasts of plants, that is found in apicomplexan parasites such as the causative agents of Malaria Plasmodium spp. It occurs throughout the Apicomplexa and is an ancient feature of this group acquired by the process of endosymbiosis. Like plant chloroplasts, apicoplasts are semi-autonomous with their own genome and expression machinery. In addition, apicoplasts import numerous proteins encoded by nuclear genes. These nuclear genes largely derive from the endosymbiont through a process of intracellular gene relocation. The exact role of a plastid in parasites is uncertain but early clues indicate synthesis of lipids, heme and isoprenoids as possibilities. The various metabolic processes of the apicoplast are potentially excellent targets for drug therapy.

Comparative Plastid Genomics of Non-Photosynthetic Chrysophytes: Genome Reduction and Compaction

“…A genome-wide comparison of synteny shows that plastid gene order in the Spumella-like flagellates is almost identical to that of photosynthetic chrysophytes (Figure 2), with the complete absence of the photosynthesis-related genes accounting for the bulk of the differences in genome size. We also carried out comparative genomic studies of plastid housekeeping genes in non-photosynthetic species among the red alga-derived plastids, including the "apicoplast" genome of the malaria parasite Plasmodium falciparum (Wilson et al, 1996;Waller and McFadden, 2005), colorless cryptophyte Cryptomonas species (Donaher et al, 2009;Tanifuji et al, 2020), and the colorless diatom Nitzschia sp. (Kamikawa et al, 2018).…”

“…(Knauf and Hachtel, 2002;Borza et al, 2005;Suzuki et al, 2018), the parasitic plant Epifagus virginiana (de Pamphilis and Palmer, 1990), members of the free-living green algal genus Polytoma (Nedelcu, 2001;Figueroa-Martinez et al, 2017), and the euglenoid alga Euglena longa (Gockel and Hachtel, 2000). Additionally, genome-containing non-photosynthetic plastids of red-algal secondary endosymbiotic origin are diverse in nature, and can be found in the malaria parasite Plasmodium falciparum (Wilson et al, 1996;Waller and McFadden, 2005), the cryptophyte Cryptomonas paramecium (Donaher et al, 2009;Tanifuji et al, 2020), the colorless diatom Nitzschia species. (Kamikawa et al, 2018), and the chrysophyte "Spumella" sp.…”

Co-Crystallization of Plant-Derived Antimalarial Drugs: An Alternate Technique for Improved Physicochemical Qualities and Antimalarial Drug Synergy

“…Naphthoquinones such as atovaquone were identified and have shown antimalarial activity due to their quinonic nature [51,52]. Plant-based quinones including 2-acetylnaphtho-[2,3b]-furan-4,9-dione and plumbagin high activity against P. berghei (IC50 = 0.002 μgml −1 ) and P. falciparum (IC50 = 0.05 μgml −1 ) respectively (Figure 3) [50,53,54].…”

Reevaluation of theToxoplasma gondiiandNeospora caninumgenomes reveals misassembly, karyotype differences and chromosomal rearrangements

“…The apicoplast is a relic non-photosynthetic chloroplast-like organelle of bacterial origin present in most apicomplexan parasites, whereby essential lipid synthesis occurs 33,34 . This organelle is of great importance as it has been validated as the target of anti-parasitic drugs such as clindamycin 34 .…”