title: Mia40, a novel factor for protein import into the intermembrane space of mitochondria is able to bind metal ions.
abstract: Many proteins located in the intermembrane space (IMS) of mitochondria are characterized by a low molecular mass, contain highly conserved cysteine residues and coordinate metal ions. Studies on one of these proteins, Tim13, revealed that net translocation across the outer membrane is driven by metal-dependent folding in the IMS . We have identified an essential component, Mia40/Tim40/Ykl195w, with a highly conserved domain in the IMS that is able to bind zinc and copper ions. In cells lacking Mia40, the endogenous levels of Tim13 and other metal-binding IMS proteins are strongly reduced due to the impaired import of these proteins. Furthermore, Mia40 directly interacts with newly imported Tim13 protein. We conclude that Mia40 is the first essential component of a specific translocation pathway of metal-binding IMS proteins.
authors.affiliation: Adolf-Butenandt-Institut für Physiologische Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5, D-81377 München, Germany.
authors.forename: Nadia
authors.initials: N
authors.lastname: Terziyska
authors.forename: Thomas
authors.initials: T
authors.lastname: Lutz
authors.forename: Christian
authors.initials: C
authors.lastname: Kozany
authors.forename: Dejana
authors.initials: D
authors.lastname: Mokranjac
authors.forename: Nikola
authors.initials: N
authors.lastname: Mesecke
authors.forename: Walter
authors.initials: W
authors.lastname: Neupert
authors.forename: Johannes M
authors.initials: JM
authors.lastname: Herrmann
authors.forename: Kai
authors.initials: K
authors.lastname: Hell
mesh_terms: D000595:Amino Acid Sequence / Q000235:genetics; D002457:Cell Extracts / Q000737:chemistry; D017124:Conserved Sequence / Q000235:genetics; D003300:Copper / Q000378:metabolism; D007425:Intracellular Membranes / Q000378:metabolism; D007477:Ions / Q000378:metabolism; D008928:Mitochondria / Q000378:metabolism*; D033681:Mitochondrial Membrane Transport Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D008969:Molecular Sequence Data; D021381:Protein Transport; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D017384:Sequence Deletion / Q000235:genetics; D015032:Zinc / Q000378:metabolism
chemical_list: D002457:Cell Extracts; D007477:Ions; C495320:MIA40 protein, S cerevisiae; D033681:Mitochondrial Membrane Transport Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D029701:Saccharomyces cerevisiae Proteins; C403093:TIM13 protein, S cerevisiae; D003300:Copper; D015032:Zinc