scholarly journals NapF Is a Cytoplasmic Iron-Sulfur Protein Required for Fe-S Cluster Assembly in the Periplasmic Nitrate Reductase

2004 ◽  
Vol 279 (48) ◽  
pp. 49727-49735 ◽  
Author(s):  
M. Francisca Olmo-Mira ◽  
Mónica Gavira ◽  
David J. Richardson ◽  
Francisco Castillo ◽  
Conrado Moreno-Vivián ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Cluster Assembly ◽  
Periplasmic Nitrate Reductase ◽  
Iron Sulfur ◽  
Sulfur Protein ◽  
Iron Sulfur Protein

scholarly journals Thio Modification of Yeast Cytosolic tRNA Is an Iron-Sulfur Protein-Dependent Pathway

2007 ◽  
Vol 27 (8) ◽  
pp. 2841-2847 ◽  
Author(s):  
Yumi Nakai ◽  
Masato Nakai ◽  
Roland Lill ◽  
Tsutomu Suzuki ◽  
Hideyuki Hayashi
Keyword(s):  
Scaffold Proteins ◽  
Yeast Cells ◽  
Cluster Assembly ◽  
Cysteine Desulfurase ◽  
S Protein ◽  
Iron Sulfur ◽  
Severe Impairment ◽  
Sulfur Protein ◽  
Iron Sulfur Protein ◽  
Dependent Pathway

ABSTRACT Defects in the yeast cysteine desulfurase Nfs1 cause a severe impairment in the 2-thio modification of uridine of mitochondrial tRNAs (mt-tRNAs) and cytosolic tRNAs (cy-tRNAs). Nfs1 can also provide the sulfur atoms of the iron-sulfur (Fe/S) clusters generated by the mitochondrial and cytosolic Fe/S cluster assembly machineries, termed ISC and CIA, respectively. Therefore, a key question remains as to whether the biosynthesis of Fe/S clusters is a prerequisite for the 2-thio modification of the tRNAs in both of the subcellular compartments of yeast cells. To elucidate this question, we asked whether mitochondrial ISC and/or cytosolic CIA components besides Nfs1 were involved in the 2-thio modification of these tRNAs. We demonstrate here that the three CIA components, Cfd1, Nbp35, and Cia1, are required for the 2-thio modification of cy-tRNAs but not of mt-tRNAs. Interestingly, the mitochondrial scaffold proteins Isu1 and Isu2 are required for the 2-thio modification of the cy-tRNAs but not of the mt-tRNAs, while mitochondrial Nfs1 is required for both 2-thio modifications. These results clearly indicate that the 2-thio modification of cy-tRNAs is Fe/S protein dependent and thus requires both CIA and ISC machineries but that of mt-tRNAs is Fe/S cluster independent and does not require key mitochondrial ISC components except for Nfs1.

scholarly journals Mouse Knock-out of IOP1 Protein Reveals Its Essential Role in Mammalian Cytosolic Iron-Sulfur Protein Biogenesis

2011 ◽  
Vol 286 (18) ◽  
pp. 15797-15805 ◽  
Author(s):  
Daisheng Song ◽  
Frank S. Lee
Keyword(s):  
Mammalian Cells ◽  
Essential Role ◽  
Cluster Assembly ◽  
Iron Sulfur Cluster ◽  
Knock Out ◽  
Adult Mice ◽  
Iron Sulfur ◽  
Sulfur Protein ◽  
Iron Sulfur Protein ◽  
Cellular Compartments

Iron-sulfur proteins play an essential role in a variety of biologic processes and exist in multiple cellular compartments. The biogenesis of these proteins has been the subject of extensive investigation, and particular focus has been placed on the pathways that assemble iron-sulfur clusters in the different cellular compartments. Iron-only hydrogenase-like protein 1 (IOP1; also known as nuclear prelamin A recognition factor like protein, or NARFL) is a human protein that is homologous to Nar1, a protein in Saccharomyces cerevisiae that, in turn, is an essential component of the cytosolic iron-sulfur protein assembly pathway in yeast. Previous siRNA-induced knockdown studies using mammalian cells point to a similar role for IOP1 in mammals. In the present studies, we pursued this further by knocking out Iop1 in Mus musculus. We find that Iop1 knock-out results in embryonic lethality before embryonic day 10.5. Acute, inducible global knock-out of Iop1 in adult mice results in lethality and significantly diminished activity of cytosolic aconitase, an iron-sulfur protein, in liver extracts. Inducible knock-out of Iop1 in mouse embryonic fibroblasts results in diminished activity of cytosolic but not mitochondrial aconitase and loss of cell viability. Therefore, just as with knock-out of Nar1 in yeast, we find that knock-out of Iop1/Narfl in mice results in lethality and defective cytosolic iron-sulfur cluster assembly. The findings demonstrate an essential role for IOP1 in this pathway.

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