title: The eukaryotic P loop NTPase Nbp35: an essential component of the cytosolic and nuclear iron-sulfur protein assembly machinery.
abstract: Soluble P loop NTPases represent a large protein family and are involved in diverse cellular functions. Here, we functionally characterized the first member of the Mrp/Nbp35 subbranch of this family, the essential Nbp35p of Saccharomyces cerevisiae. The protein resides in the cytosol and nucleus and carries an Fe/S cluster at its N terminus. Assembly of the Fe/S cluster requires the mitochondrial Fe/S cluster (ISC)-assembly and -export machineries. Depletion of Nbp35p strongly impairs the activity of the cytosolic Fe/S protein, isopropylmalate isomerase (Leu1p), whereas mitochondrial Fe/S enzymes are unaffected. Moreover, defects in the de novo maturation of various cytosolic and nuclear Fe/S proteins were observed in the absence of Nbp35p, demonstrating the functional involvement of Nbp35p in the biogenesis of extramitochondrial Fe/S proteins. Furthermore, Nbp35p genetically interacts with the closely similar P loop NTPase, Cfd1p, and the hydrogenase-like Nar1p, both of which were recently shown to perform a crucial function in cytosolic and nuclear Fe/S protein biogenesis. Hence, our study suggests that eukaryotic Nbp35 NTPases function in Fe/S protein maturation. The findings provide strong evidence for the existence of a highly conserved and essential machinery dedicated to assembling cytosolic and nuclear Fe/S proteins.
authors.affiliation: Institut für Zytobiologie und Zytopathologie, Philipps-Universität Marburg, Robert-Koch-Strasse 6, D-35033 Marburg, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Hausmann
authors.forename: Daili J
authors.initials: DJ
authors.lastname: Aguilar Netz
authors.forename: Janneke
authors.initials: J
authors.lastname: Balk
authors.forename: Antonio J
authors.initials: AJ
authors.lastname: Pierik
authors.forename: Ulrich
authors.initials: U
authors.lastname: Mühlenhoff
authors.forename: Roland
authors.initials: R
authors.lastname: Lill
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism / Q000502:physiology*; D002467:Cell Nucleus / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism*; D019204:GTP-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D007506:Iron-Sulfur Proteins / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D011485:Protein Binding; D011994:Recombinant Proteins / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism / Q000502:physiology*
chemical_list: D007506:Iron-Sulfur Proteins; C102265:NBP35 protein, S cerevisiae; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; D000251:Adenosine Triphosphatases; D019204:GTP-Binding Proteins
references.citation: EMBO Rep. 2001 Aug;2(8):715-20
references.pmid: 11493598
references.citation: EMBO J. 2004 May 19;23(10):2105-15
references.pmid: 15103330
references.citation: Gene. 1995 Apr 14;156(1):119-22
references.pmid: 7737504
references.citation: Nucleic Acids Res. 1992 Mar 25;20(6):1425
references.pmid: 1561104
references.citation: J Biochem. 1999 Jul;126(1):10-8
references.pmid: 10393315
references.citation: Methods Cell Biol. 2001;65:37-51
references.pmid: 11381604
references.citation: Curr Opin Chem Biol. 2003 Apr;7(2):166-73
references.pmid: 12714048
references.citation: EMBO J. 2003 Sep 15;22(18):4826-35
references.pmid: 12970194
references.citation: J Biol Chem. 1998 Nov 20;273(47):31138-44
references.pmid: 9813017
references.citation: J Bacteriol. 2003 Jan;185(1):98-106
references.pmid: 12486045
references.citation: Mol Microbiol. 2003 Apr;48(2):295-303
references.pmid: 12675792
references.citation: J Biol Chem. 2001 Jan 12;276(2):1503-9
references.pmid: 11035018
references.citation: Nature. 2003 Oct 16;425(6959):686-91
references.pmid: 14562095
references.citation: J Biol Chem. 1999 Nov 12;274(46):33025-34
references.pmid: 10551871
references.citation: J Mol Biol. 2002 Mar 15;317(1):41-72
references.pmid: 11916378
references.citation: Proc Natl Acad Sci U S A. 1999 Aug 31;96(18):10206-11
references.pmid: 10468587
references.citation: Cell Mol Life Sci. 2002 Oct;59(10):1658-65
references.pmid: 12475176
references.citation: Trends Biochem Sci. 2005 Mar;30(3):133-41
references.pmid: 15752985
references.citation: EMBO J. 2005 Feb 9;24(3):589-98
references.pmid: 15660134
references.citation: Methods Enzymol. 1991;194:3-21
references.pmid: 2005794
references.citation: Trends Biochem Sci. 2000 Aug;25(8):352-6
references.pmid: 10916152
references.citation: Proc Natl Acad Sci U S A. 2003 Aug 19;100(17):9762-7
references.pmid: 12886008
references.citation: J Biol Chem. 2004 Aug 27;279(35):36906-15
references.pmid: 15220327
references.citation: EMBO J. 1999 Jul 15;18(14):3981-9
references.pmid: 10406803
references.citation: Mol Cell Biol. 2004 Jun;24(11):4848-57
references.pmid: 15143178
references.citation: EMBO J. 2005 Feb 9;24(3):580-8
references.pmid: 15660135
references.citation: EMBO J. 2003 Sep 15;22(18):4815-25
references.pmid: 12970193
references.citation: Proc Natl Acad Sci U S A. 2000 Feb 1;97(3):1050-5
references.pmid: 10655482
references.citation: Hum Mol Genet. 2002 Aug 15;11(17):2025-36
references.pmid: 12165564
references.citation: Gene. 1996 Oct 31;178(1-2):97-106
references.pmid: 8921898