title: Bacterial signal peptide recognizes HeLa cell mitochondrial import receptors and functions as a mitochondrial leader sequence.
abstract: Phage display was used to identify new components of the mammalian mitochondrial receptor complex using Tom20 as a binding partner. Two peptides were identified. One had partial identity (SMLTVMA) with a bacterial signal peptide from Toho-1, a periplasmic protein. The other had partial identity with a mitochondrial inner membrane glutamate carrier. The bacterial signal peptide could carry a protein into mitochondria both in vivo and in vitro. The first six residues of the sequence, SMLTVM, were necessary for import but the two adjacent arginine residues in the 30-amino-acid leader were not critical for import. The signal peptides of Escherichia coli beta-lactamase and Bacillsus subtilis lipase could not carry proteins into mitochondria. Presumably, the Toho-1 leader can adopt a structure compatible for recognition by the import apparatus.
authors.affiliation: Department of Biochemistry, Purdue University, West Lafayette, Indiana 47907-2063, USA.
authors.forename: A
authors.initials: A
authors.lastname: Mukhopadhyay
authors.forename: L
authors.initials: L
authors.lastname: Ni
authors.forename: C-S
authors.initials: CS
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Weiner
mesh_terms: D000595:Amino Acid Sequence; D027322:Amino Acid Transport System X-AG / Q000737:chemistry / Q000378:metabolism; D001412:Bacillus subtilis; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D049452:Green Fluorescent Proteins / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D008049:Lipase / Q000737:chemistry / Q000378:metabolism; D008564:Membrane Potentials; D008928:Mitochondria / Q000235:genetics / Q000378:metabolism*; D024101:Mitochondrial Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D019151:Peptide Library; D011485:Protein Binding; D021382:Protein Sorting Signals / Q000502:physiology*; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D001618:beta-Lactamases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D027322:Amino Acid Transport System X-AG; D029968:Escherichia coli Proteins; D024101:Mitochondrial Proteins; D009842:Oligopeptides; D019151:Peptide Library; D021382:Protein Sorting Signals; D011993:Recombinant Fusion Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; D008049:Lipase; D001618:beta-Lactamases; C495977:beta-lactamase Toho-1, E coli