Malaria parasites are responsible for 300-500 million infections and 2-3 million deaths annually. During the asexual stages of development in red blood cells, parasites acquire certain nutrients from human serum while retaining the ability to synthesize others. We are studying an essential enzyme cofactor called lipoate and its metabolism in Plasmodium falciparum. Our recent studies indicate that malaria parasites contain a metabolic pathway to synthesize lipoate de novo from intermediates of fatty acid biosynthesis as well as two mechanisms for scavenging lipoate from human serum. These pathways appear to reside in different subcellular compartments in the parasite and may be independent and essential for parasite survival. The proposed studies will employ biochemical, cell biology and genetic approaches to investigate these unexplored pathways and establish the roles of synthesized and host-derived lipoate in parasite survival.
Specific Aim 1 will define the activities and organization of the P. falciparum lipoate biosynthetic machinery and the role of synthesized lipoate in parasite survival.
Specific Aim 2 will define the role of exogenous lipoate in parasite survival, its distribution in the parasite, and the activities and organization of the P. falciparum lipoate scavenging pathways. These studies could establish the existence of an intracellular metabolite trafficking pathway between the apicoplast organelle and the mitochondrion of malaria parasites. Alternatively, these studies could demonstrate that P. falciparum parasites are auxotrophic for lipoate despite the existence of a lipoate biosynthetic pathway. Proteins responsible for the metabolism of lipoate may ultimately prove to be attractive targets for therapeutic intervention - especially since inhibitors could act synergistically with known inhibitors of P. falciparum fatty acid biosynthesis. ? ? ?

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
1R01AI065853-01A1
Application #
7094051
Study Section
Pathogenic Eukaryotes Study Section (PTHE)
Program Officer
Rogers, Martin J
Project Start
2006-02-01
Project End
2011-01-31
Budget Start
2006-02-01
Budget End
2007-01-31
Support Year
1
Fiscal Year
2006
Total Cost
$403,799
Indirect Cost
Name
Johns Hopkins University
Department
Microbiology/Immun/Virology
Type
Schools of Public Health
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Dellibovi-Ragheb, Teegan A; Jhun, Hugo; Goodman, Christopher D et al. (2018) Host biotin is required for liver stage development in malaria parasites. Proc Natl Acad Sci U S A 115:E2604-E2613
Guerra, Alfredo J; Afanador, Gustavo A; Prigge, Sean T (2017) Crystal structure of lipoate-bound lipoate ligase 1, LipL1, from Plasmodium falciparum. Proteins 85:1777-1783
Gisselberg, Jolyn E; Dellibovi-Ragheb, Teegan A; Matthews, Krista A et al. (2013) The suf iron-sulfur cluster synthesis pathway is required for apicoplast maintenance in malaria parasites. PLoS Pathog 9:e1003655
Falkard, Brie; Kumar, T R Santha; Hecht, Leonie-Sophie et al. (2013) A key role for lipoic acid synthesis during Plasmodium liver stage development. Cell Microbiol 15:1585-604
Dellibovi-Ragheb, Teegan A; Gisselberg, Jolyn E; Prigge, Sean T (2013) Parasites FeS up: iron-sulfur cluster biogenesis in eukaryotic pathogens. PLoS Pathog 9:e1003227
Gallagher, John R; Matthews, Krista A; Prigge, Sean T (2011) Plasmodium falciparum apicoplast transit peptides are unstructured in vitro and during apicoplast import. Traffic 12:1124-38
Gallagher, John R; Prigge, Sean T (2010) Plasmodium falciparum acyl carrier protein crystal structures in disulfide-linked and reduced states and their prevalence during blood stage growth. Proteins 78:575-88
Coppens, Isabelle; Sullivan, David J; Prigge, Sean T (2010) An update on the rapid advances in malaria parasite cell biology. Trends Parasitol 26:305-10
Spalding, Maroya D; Prigge, Sean T (2010) Lipoic acid metabolism in microbial pathogens. Microbiol Mol Biol Rev 74:200-28
Du, Yu; Gisselberg, Jolyn E; Johnson, Jacob D et al. (2010) Lactococcus lactis fabH, encoding beta-ketoacyl-acyl carrier protein synthase, can be functionally replaced by the Plasmodium falciparum congener. Appl Environ Microbiol 76:3959-66

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