Chapter 12 Controlled expression of iron-sulfur cluster assembly components for respiratory chain complexes in mammalian cells.
Three of the respiratory chain complexes contain essential iron-sulfur (Fe/S) cluster prosthetic groups. Besides respiration, these ancient inorganic cofactors are also necessary for numerous other fundamental biochemical processes in virtually every known organism. Both the synthesis of Fe/S clusters and their delivery to apoproteins depend on the concerted function of specialized, often dedicated, proteins located in the mitochondria and cytosol of eukaryotes. Impaired function of the mitochondria-located Fe/S cluster (ISC) assembly machinery affects all cellular Fe/S proteins, including enzymes of the respiratory chain, NADH: ubiquinone oxidoreductase (complex I; eight Fe/S clusters), succinate: ubiquinone oxidoreductase (complex II; three Fe/S clusters), and cytochrome bc(1) complex (complex III; one Fe/S cluster). Here, we describe strategies and techniques both to deprive respiratory chain proteins of their Fe/S cofactors and to study changes in activity and composition of these proteins. As examples, we present the results of the depletion of two types of Fe/S biogenesis proteins, huNfs1 and huInd1, in a human tissue culture model. The ISC assembly component huNfs1 is required for biogenesis of all cellular Fe/S proteins, its loss exerting pleiotropic effects, whereas huInd1 is specific for Fe/S cluster maturation of complex I. Disorders in Fe/S cluster assembly are candidate causes for defects in respiratory complex assembly of unknown etiology.
Institut für Zytobiologie and Zytopathologie, Philipps-Universität, Marburg, Germany.
Oliver
O
Stehling
Alex D
AD
Sheftel
Roland
R
Lill
D001345:Autoradiography; D001483:Base Sequence; D042967:Electron Transport Complex I / Q000378:metabolism*; D015180:Electrophoresis, Gel, Two-Dimensional; D018274:Electroporation; D006367:HeLa Cells; D006801:Humans; D007506:Iron-Sulfur Proteins / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference; D034741:RNA, Small Interfering; D014162:Transfection
D007506:Iron-Sulfur Proteins; D034741:RNA, Small Interfering; D042967:Electron Transport Complex I