Abstract
IMP1 encodes a subunit of the mitochondrial inner membrane peptidase responsible for the proteolytic processing of cytochrome oxidase subunit 2 (Cox2) and cytochromeb 2 (Cytb2). The molecular defect in animp1 mutation and the characterisation of a high-copy-number suppressor is described. A delection of the suppressor region causes respiration deficiency. The DNA sequence revealed three very small overlapping ORFs. Constructs which carried termination codons within the ORFs or lacked ATG initiation codons still retained complementing activity on a high-copy-number plasmid. Nevertheless, the possibility that the suppressor acts at DNA or RNA level could be excluded. Subcloning of the ORFs, complementation analysis in low-copy-number plasmids and transcript mapping identified the 222 bp ORF as the suppressor gene designatedSOM1. TheSOM1 gene is transcribed into a 375 bp polyadenylated RNA and the deduced amino acid sequence predicts a small protein of 8.4 kDa with no significant sequence similarity to known proteins. In thesom1 deletion mutant, proteolytic processing of the Cox2 precursor is prevented and Cytb2 is strongly reduced.SOM1 represents a new small gene which encodes a novel factor that is essential for the correct function of the Imp1 peptidase and/or the protein sorting machinery.
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Bauer M, Behrens M, Esser K, Michaelis G, Pratje E (1994)PET1402, a nuclear gene required for proteolytic processing of cytochrome oxidase subunit 2 in yeast. Mol Gen Genet 245:272–278
Behrens M, Michaelis G, Pratje E (1991) Mitochondrial inner membrane protease 1 ofSaccharomyces cerevisiae shows sequence similarity to theEscherichia coli leader peptidase. Mol Gen Genet 228:167–176
Bennetzen JC, Hall BD (1982) Codon selection in yeast. J Biol Chem 257:3026–3031
Boles E, Liebetrau W, Hofmann M, Zimmermann FK (1994) A family of hexosephosphate mutases inSaccharomyces cerevisiae. Eur J Biochem 220:83–96
Bonnefoy N, Kermorgant M, Groudinsky O, Minet M, Slonimski PP, Dujardin G (1994) Cloning of a human gene involved in cytochrome oxidase assembly by functional complementation of an oxa1−mutation inSaccharomyces cerevisiae. Proc Natl Acad Sci USA 91:11978–11982
Crespi MD, Jurkevitch E, Poiret M, d'Aubenton-Carafa Y, Petrovics G, Kondorosi E, Kondorosi A (1994)enod40, a gene expressed during nodule organogenesis, codes for a non-translatable RNA involved in plant growth. EMBO J 13:5099–5112
Dalbey RE, von Heijne G (1992) Signal peptidases in prokaryotes and eukaryotes — a new protease family. Trends Biochem Sci 17:474–478
Glerum DM, Koerner TJ, Tzagoloff A (1995) Cloning and characterization ofCOX14, whose product is required for assembly of yeast cytochrome oxidase. J Biol Chem 270:15585–15590
Hahne K, Haucke V, Ramage L, Schatz G (1994) One gene encodes two isoforms of NADH-cytochromeb5 reductase in different mitochondrial subcompartments. Cell 79:829–839
Hanahan D (1983) Studies on transformation ofEscherichia coli with plasmids. J Mol Biol 166:557–580
Hannavy K, Schatz G (1995) Protein import into mitochondria. In: Papa S, Tager JM (eds)Biochemistry of cell membranes. Birkhäuser Verlag, Basel, pp 55–74
Henikoff S, Cohen EH (1984) Sequences responsible for transcription termination on a gene segment inSaccharomyces cerevisiae. Mol Cell Biol 4:1515–1520
Hill JE, Myers AM, Koerner TJ, Tzagoloff A (1986) Yeast/E. coli shuttle vectors with multiple unique restriction sites. Yeast 2:163–167
Hinnebusch AG, Liebman SW (1991) Protein synthesis and translational control inSaccharomyces cerevisiae. In: Broach JR, Pringle J, Jones E (eds) The molecular and cellular biology of the yeastSaccharomyces cerevisiae. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York, pp 627–735
Hofmann M, Boles E, Zimmermann FK (1994) Characterization of the essential yeast gene encoding N-acetylglucosamine-phosphate mutase. Eur J Biochem 221:741–747
Holm C, Meeks-Wagner DW, Fangman WL, Botstein D (1986) A rapid, efficient method for isolating DNA from yeast. Gene 42:169–173
Innis MA, Gelfand DH, Sninsky JJ, White TJ (eds) (1990) PCR protocols — a guide to methods and applications. Academic Press, San Diego
Kassenbrock CK, Cao N, Douglas MG (1996) Genetic and biochemical characterization of ISP6, a small mitochondrial outer membrane protein associated with the protein translocation complex. EMBO J 12:3023–3034
Köhrer K, Domdey H (1991) Preparation of high molecular weight RNA. Methods Enzymol 194:398–401
Laemmli UK (1970) Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature 227:680–684
Lauermann V (1991) Ethanol improves the transformation efficiency of intact yeast cells. Curr Genet 20:1–3
Liu H, Krizek J, Bretscher A (1992) Construction of a GAL1-regulated yeast cDNA expression library and its application to the identification of genes whose overexpression causes lethality in yeast. Genetics 132:665–673
McEwen JE, Cameron VL, Poyton RO (1985) A rapid method for isolation and screening of cytochromec oxidase-deficient mutants ofSaccharomyces cerevisiae. J Bacteriol 161:831–835
Michaelis G, Mannhaupt G, Pratje E, Fischer E, Naggert J, Schweizer E (1982) Mitochondrial translation products in nuclear respiration-deficient pet mutants ofSaccharomyces cerevisiae. In: Slonimski PP, Borst P, Attardi G (eds) Mitochondrial genes. Cold Spring Harbor Laboratory, Cold Spring Harbor, New York, pp 311–321
Moehle CM, Aynardi MW, Kolodny MR, Park FJ, Jones EW (1987) Protease B ofSaccharomyces cerevisiae: Isolation and regulation of thePRB1 structural gene. Genetics 115:255–263
Nunnari J, Fox TD, Walter P (1993) A mitochondrial protease with two catalytic subunits of nonoverlapping specificities. Science 262:1997–2004
Orr-Weaver TL, Szostak JW, Rothstein RJ (1983) Genetic application of yeast transformation with linear and gapped plasmids. Methods Enzymol 101:228–245
Pfanner N, Craig EA, Meijer M (1994) The protein import machinery of the mitochondrial inner membrane. Trends Biochem Sci 19:368–372
Poyton RO, Duhl DMJ, Clarkson GHD (1992) Protein export from the mitochondrial matrix. Trends Cell Biol 2:369–375
Pratje E, Michaelis G (1977) Allelism studies of mitochondrial mutants resistant to antimycin A or funiculosin inSaccharomyces cerevisiae. Mol Gen Genet 152:167–174
Pratje E, Guiard D (1986) One nuclear gene controls the removal of transient pre-sequences from two yeast proteins: one encoded by the nuclear, the other by the mitochondrial genome. EMBO J 5:1312–1317
Pratje E, Mannhaupt G, Michaelis G, Beyreuther K (1983) A nuclear mutation prevents processing of a mitochondrially encoded membrane protein inSaccharomyces cerevisiae. EMBO J 2:1049–1054
Rose MD, Novick P, Thomas JH, Botstein D, Fink GR (1987) ASaccharomyces cerevisiae genomic plasmid bank based on a centromere-containing shuttle vector. Gene 60:237–243
Rothstein RJ (1983) One-step gene disruption in yeast. Methods Enzymol 101:202–211
Ryan KR, Jensen RE (1995) Protein translocation across mitochondrial membranes: what a long, strange trip it is. Cell 83:517–519
Sambrook J, Fritsch EF, Maniatis T (1989) Molecular cloning: a laboratory manual (2nd edn) Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York
Sanger F, Nicklen S, Coulson AR (1977) DNA sequencing with chain termination inhibitors. Proc Natl Acad Sci USA 74:5463–5467
Schneider A, Behrens M, Scherer P, Pratje E, Michaelis G, Schatz G (1991) Inner membrane protease I, an enzyme mediating intramitochondrial protein sorting in yeast. EMBO J 10:247–254
Schwartz E, Neupert W (1994) Mitochondrial protein import: mechanisms, components, and energetics. Biochim Biophys Acta 1187:270–274
Taylor JW, Ott J, Eckstein F (1985) The rapid generation of oligonucleotide-directed mutations at high frequency using phosphorothioate-modified DNA. Nucleic Acids Res 13:8764–8785
Van Dijl JM, de Jong A, Vehmaanperä J, Venema G, Bron S (1992) Signal peptidase I ofBacillus subtilis: patterns of conserved amino acids in prokaryotic and cukaryotic type I signal peptidases. EMBO J 11:2819–2828
Verner K (1993) Co-translational protein import into mitochondria: an alternative view. Trends Biochem Sci 18:366–371
Watanabe Y, Yamamoto M (1994)S. pombe mei2 + encodes an RNA-binding protein essential for premeiotic DNA synthesis and meiosis I, which cooperates with a novel RNA species meiRNA. Cell 78:487–498
Yaffe MP, Schatz G (1984) Two nuclear mutations that block mitochondrial protein import in yeast. Proc Natl Acad Sci USA 81:4819–4823
Zaret KS, Sherman F (1982) DNA sequences required for efficient transcription termination in yeast. Cell 28:563–573
Ziaja K, Michaelis G, Lisowsky T (1993) Nuclear control of the messenger RNA expression for mitochondrial ATPase subunit 9 in a new yeast mutant. J Mol Biol 229:909–916
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Communicated by C. P. Hollenberg
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Esser, K., Pratje, E. & Michaelis, G. SOM 1, a small new gene required for mitochondrial inner membrane peptidase function inSaccharomyces cerevisiae . Molec. Gen. Genet. 252, 437–445 (1996). https://doi.org/10.1007/BF02173009
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DOI: https://doi.org/10.1007/BF02173009