GTP is required for iron-sulfur cluster biogenesis in mitochondria.
Iron-sulfur (Fe-S) cluster biogenesis in mitochondria is an essential process and is conserved from yeast to humans. Several proteins with Fe-S cluster cofactors reside in mitochondria, including aconitase [4Fe-4S] and ferredoxin [2Fe-2S]. We found that mitochondria isolated from wild-type yeast contain a pool of apoaconitase and machinery capable of forming new clusters and inserting them into this endogenous apoprotein pool. These observations allowed us to develop assays to assess the role of nucleotides (GTP and ATP) in cluster biogenesis in mitochondria. We show that Fe-S cluster biogenesis in isolated mitochondria is enhanced by the addition of GTP and ATP. Hydrolysis of both GTP and ATP is necessary, and the addition of ATP cannot circumvent processes that require GTP hydrolysis. Both in vivo and in vitro experiments suggest that GTP must enter into the matrix to exert its effects on cluster biogenesis. Upon import into isolated mitochondria, purified apoferredoxin can also be used as a substrate by the Fe-S cluster machinery in a GTP-dependent manner. GTP is likely required for a common step involved in the cluster biogenesis of aconitase and ferredoxin. To our knowledge this is the first report demonstrating a role of GTP in mitochondrial Fe-S cluster biogenesis.
Amutha
Boominathan
B
Department of Pharmacology and Physiology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey 07101.
Gordon
Donna M
DM
Department of Pharmacology and Physiology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey 07101.
Gu
Yajuan
Y
Department of Pharmacology and Physiology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey 07101.
Lyver
Elise R
ER
Department of Medicine, Division of Hematology-Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
Dancis
Andrew
A
Department of Medicine, Division of Hematology-Oncology, University of Pennsylvania, Philadelphia, Pennsylvania 19104.
Pain
Debkumar
D
Department of Pharmacology and Physiology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey 07101. Electronic address: painde@umdnj.edu.
D000154:Aconitate Hydratase / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D001051:Apoenzymes / Q000378:metabolism; D013437:Carbon-Sulfur Lyases / Q000378:metabolism; D005288:Ferredoxins / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D020035:Holoenzymes / Q000378:metabolism; D006868:Hydrolysis; D007506:Iron-Sulfur Proteins / Q000096:biosynthesis*; D007553:Isotope Labeling; D008928:Mitochondria / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism; D013462:Sulfur Radioisotopes
D001051:Apoenzymes; D005288:Ferredoxins; D020035:Holoenzymes; D007506:Iron-Sulfur Proteins; D029701:Saccharomyces cerevisiae Proteins; D013462:Sulfur Radioisotopes; D006160:Guanosine Triphosphate; D000255:Adenosine Triphosphate; D000154:Aconitate Hydratase; D013437:Carbon-Sulfur Lyases; C080546:cysteine desulfurase