Redox-dependent lipoylation of mitochondrial proteins in Plasmodium falciparum.
Mol Microbiol
; 94(1): 156-71, 2014 Oct.
Article
en En
| MEDLINE
| ID: mdl-25116855
ABSTRACT
Lipoate scavenging from the human host is essential for malaria parasite survival. Scavenged lipoate is covalently attached to three parasite proteins the H-protein and the E2 subunits of branched chain amino acid dehydrogenase (BCDH) and α-ketoglutarate dehydrogenase (KDH). We show mitochondrial localization for the E2 subunits of BCDH and KDH, similar to previously localized H-protein, demonstrating that all three lipoylated proteins reside in the parasite mitochondrion. The lipoate ligase 1, LipL1, has been shown to reside in the mitochondrion and it catalyses the lipoylation of the H-protein; however, we show that LipL1 alone cannot lipoylate BCDH or KDH. A second mitochondrial protein with homology to lipoate ligases, LipL2, does not show ligase activity and is not capable of lipoylating any of the mitochondrial substrates. Instead, BCDH and KDH are lipoylated through a novel mechanism requiring both LipL1 and LipL2. This mechanism is sensitive to redox conditions where BCDH and KDH are exclusively lipoylated under strong reducing conditions in contrast to the H-protein which is preferentially lipoylated under less reducing conditions. Thus, malaria parasites contain two different routes of mitochondrial lipoylation, an arrangement that has not been described for any other organism.
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1
Base de datos:
MEDLINE
Asunto principal:
Plasmodium falciparum
/
Proteínas Protozoarias
/
Proteínas Mitocondriales
Idioma:
En
Revista:
Mol Microbiol
Asunto de la revista:
BIOLOGIA MOLECULAR
/
MICROBIOLOGIA
Año:
2014
Tipo del documento:
Article