Human mitochondrial MIA40 (CHCHD4) is a component of the Fe-S cluster export machinery.
Mitochondria play an essential role in synthesis and export of iron-sulfur (Fe-S) clusters to other sections of a cell. Although the mechanism of Fe-S cluster synthesis is well elucidated, information on the identity of the proteins involved in the export pathway is limited. The present study identifies hMIA40 (human mitochondrial intermembrane space import and assembly protein 40), also known as CHCHD4 (coiled-coil-helix-coiled-coil-helix domain-containing 4), as a component of the mitochondrial Fe-S cluster export machinery. hMIA40 is an iron-binding protein with the ability to bind iron in vivo and in vitro. hMIA40 harbours CPC (Cys-Pro-Cys) motif-dependent Fe-S clusters that are sensitive to oxidation. Depletion of hMIA40 results in accumulation of iron in mitochondria concomitant with decreases in the activity and stability of Fe-S-containing cytosolic enzymes. Intriguingly, overexpression of either the mitochondrial export component or cytosolic the Fe-S cluster assembly component does not have any effect on the phenotype of hMIA40-depleted cells. Taken together, our results demonstrate an indispensable role for hMIA40 for the export of Fe-S clusters from mitochondria.
Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad 500046, India.
Anjaneyulu
A
Murari
Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad 500046, India.
Venkata Ramana
VR
Thiriveedi
Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad 500046, India.
Fareed
F
Mohammad
Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad 500046, India.
Viswamithra
V
Vengaldas
Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad 500046, India.
Madhavi
M
Gorla
Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad 500046, India.
Prasad
P
Tammineni
Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad 500046, India.
Thanuja
T
Krishnamoorthy
Department of Biochemistry, University of Hyderabad, Gachibowli, Hyderabad 500046, India nareshuohyd@gmail.com nbvssl@uohyd.ernet.in.
Naresh Babu V
NB
Sepuri
D020816:Amino Acid Motifs; D001693:Biological Transport, Active / Q000502:physiology; D006801:Humans; D007501:Iron / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D013455:Sulfur / Q000378:metabolism*
C507282:CHCHD4 protein, human; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D013455:Sulfur; D007501:Iron
CIA; GPAT; hMIA40; iron export; iron–sulfur (Fe–S) cluster; mitochondria