scholarly journals Decision letter: The mitochondrial acyl carrier protein (ACP) coordinates mitochondrial fatty acid synthesis with iron sulfur cluster biogenesis

2016 ◽  
eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Jonathan G Van Vranken ◽  
Mi-Young Jeong ◽  
Peng Wei ◽  
Yu-Chan Chen ◽  
Steven P Gygi ◽  
...  

Mitochondrial fatty acid synthesis (FASII) and iron sulfur cluster (FeS) biogenesis are both vital biosynthetic processes within mitochondria. In this study, we demonstrate that the mitochondrial acyl carrier protein (ACP), which has a well-known role in FASII, plays an unexpected and evolutionarily conserved role in FeS biogenesis. ACP is a stable and essential subunit of the eukaryotic FeS biogenesis complex. In the absence of ACP, the complex is destabilized resulting in a profound depletion of FeS throughout the cell. This role of ACP depends upon its covalently bound 4’-phosphopantetheine (4-PP)-conjugated acyl chain to support maximal cysteine desulfurase activity. Thus, it is likely that ACP is not simply an obligate subunit but also exploits the 4-PP-conjugated acyl chain to coordinate mitochondrial fatty acid and FeS biogenesis.


eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Seyi Falekun ◽  
Jaime Sepulveda ◽  
Yasaman Jami-Alahmadi ◽  
Hahnbeom Park ◽  
James A Wohlschlegel ◽  
...  

Most eukaryotic cells retain a mitochondrial fatty acid synthesis (FASII) pathway whose acyl carrier protein (mACP) and 4-phosphopantetheine (Ppant) prosthetic group provide a soluble scaffold for acyl chain synthesis and biochemically couple FASII activity to mitochondrial electron transport chain (ETC) assembly and Fe-S cluster biogenesis. In contrast, the mitochondrion of Plasmodium falciparum malaria parasites lacks FASII enzymes yet curiously retains a divergent mACP lacking a Ppant group. We report that ligand-dependent knockdown of mACP is lethal to parasites, indicating an essential FASII-independent function. Decyl-ubiquinone rescues parasites temporarily from death, suggesting a dominant dysfunction of the mitochondrial ETC. Biochemical studies reveal that Plasmodium mACP binds and stabilizes the Isd11-Nfs1 complex required for Fe-S cluster biosynthesis, despite lacking the Ppant group required for this association in other eukaryotes, and knockdown of parasite mACP causes loss of Nfs1 and the Rieske Fe-S protein in ETC Complex III. This work reveals that Plasmodium parasites have evolved to decouple mitochondrial Fe-S cluster biogenesis from FASII activity, and this adaptation is a shared metabolic feature of other apicomplexan pathogens, including Toxoplasma and Babesia. This discovery unveils an evolutionary driving force to retain interaction of mitochondrial Fe-S cluster biogenesis with ACP independent of its eponymous function in FASII.


FEBS Letters ◽  
2004 ◽  
Vol 577 (1-2) ◽  
pp. 170-174 ◽  
Author(s):  
Johan G. Olsen ◽  
Anne V. Rasmussen ◽  
Penny von Wettstein-Knowles ◽  
Anette Henriksen

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Zhe Hu ◽  
Huijuan Dong ◽  
Jin-Cheng Ma ◽  
Yonghong Yu ◽  
Kai-Hui Li ◽  
...  

ABSTRACTThe precursors of the diffusible signal factor (DSF) family signals ofXanthomonas campestrispv.campestrisare 3-hydroxyacyl-acyl carrier protein (3-hydroxyacyl-ACP) thioesters having acyl chains of 12 to 13 carbon atoms produced by the fatty acid biosynthetic pathway. We report a novel 3-oxoacyl-ACP reductase encoded by theX. campestrispv.campestrisXCC0416 gene (fabG2), which is unable to participate in the initial steps of fatty acyl synthesis. This was shown by the failure of FabG2 expression to allow growth at the nonpermissive temperature of anEscherichia colifabGtemperature-sensitive strain. However, when transformed into theE. colistrain together with a plasmid bearing theVibrio harveyiacyl-ACP synthetase gene (aasS), growth proceeded, but only when the medium contained octanoic acid.In vitroassays showed that FabG2 catalyzes the reduction of long-chain (≥C8) 3-oxoacyl-ACPs to 3-hydroxyacyl-ACPs but is only weakly active with shorter-chain (C4, C6) substrates. FabG1, the housekeeping 3-oxoacyl-ACP reductase encoded within the fatty acid synthesis gene cluster, could be deleted in a strain that overexpressedfabG2but only in octanoic acid-supplemented media. Growth of theX. campestrispv.campestrisΔfabG1strain overexpressingfabG2requiredfabHfor growth with octanoic acid, indicating that octanoyl coenzyme A is elongated byX. campestrispv.campestrisfabH. Deletion offabG2reduced DSF family signal production, whereas overproduction of either FabG1 or FabG2 in the ΔfabG2strain restored DSF family signal levels.IMPORTANCEQuorum sensing mediated by DSF signaling molecules regulates pathogenesis in several different phytopathogenic bacteria, includingXanthomonas campestrispv.campestris. DSF signaling also plays a key role in infection by the human pathogenBurkholderia cepacia. The acyl chains of the DSF molecules are diverted and remodeled from a key intermediate of the fatty acid synthesis pathway. We report aXanthomonas campestrispv.campestrisfatty acid synthesis enzyme, FabG2, of novel specificity that seems tailored to provide DSF signaling molecule precursors.


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