title: Targeting capacity and conservation of PreP homologues localization in mitochondria of different species.
abstract: Mitochondrial presequences and other unstructured peptides are degraded inside mitochondria by presequence proteases (PrePs) identified in Arabidopsis thaliana (AtPreP), humans (hPreP), and yeast (Cym1/Mop112). The presequences of A. thaliana and human PreP are predicted to consist of 85 and 29 amino acids, respectively, whereas the Saccharomyces cerevisiae Cym1/Mop112 presequence contains only 7 residues. These differences may explain the reported targeting of homologous proteins to different mitochondrial subcompartments. Here we have investigated the targeting capacity of the PreP homologues' presequences. We have produced fusion constructs containing N-terminal portions of AtPreP(1-125), hPreP(1-69), and Cym1(1-40) coupled to green fluorescent protein (GFP) and studied their import into isolated plant, mammalian, and yeast mitochondria, followed by mitochondrial subfractionation. Whereas the AtPreP presequence has the capacity to target GFP into the mitochondrial matrix of all three species, the hPreP presequence only targets GFP to the matrix of mammalian and yeast mitochondria. The Cym1/Mop112 presequence has an overall much weaker targeting capacity and only ensures mitochondrial sorting in its host species yeast. Revisiting the submitochondrial localization of Cym1 revealed that endogenous Cym1/Mop112 is localized to the matrix space, as has been previously reported for the plant and human homologues. Moreover, complementation studies in yeast show that native AtPreP restores the growth phenotype of yeast cells lacking Cym1, demonstrating functional conservation.
authors.affiliation: Department of Biochemistry and Biophysics, Arrhenius Laboratories for Natural Science, Stockholm University, SE-10691 Stockholm, Sweden.
authors.forename: Nyosha
authors.initials: N
authors.lastname: Alikhani
authors.forename: Anna-Karin
authors.initials: AK
authors.lastname: Berglund
authors.forename: Tanja
authors.initials: T
authors.lastname: Engmann
authors.forename: Erika
authors.initials: E
authors.lastname: Spånning
authors.forename: F-Nora
authors.initials: FN
authors.lastname: Vögtle
authors.forename: Pavel
authors.initials: P
authors.lastname: Pavlov
authors.forename: Chris
authors.initials: C
authors.lastname: Meisinger
authors.forename: Thomas
authors.initials: T
authors.lastname: Langer
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Glaser
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D005816:Genetic Complementation Test; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D045726:Metalloproteases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009154:Mutation; D010447:Peptide Hydrolases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010455:Peptides / Q000235:genetics / Q000378:metabolism; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D012697:Serine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D013045:Species Specificity
chemical_list: D029681:Arabidopsis Proteins; D024101:Mitochondrial Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D049452:Green Fluorescent Proteins; C514899:PREP protein, human; C501750:CYM1 protein, S cerevisiae; D045726:Metalloproteases; D010447:Peptide Hydrolases; C501884:PrePI protein, Arabidopsis; C501885:PrePII protein, Arabidopsis; C511107:presequence protease PreP, Arabidopsis; D012697:Serine Endopeptidases