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. 1995 Jun;15(6):3382–3389. doi: 10.1128/mcb.15.6.3382

The mitochondrial receptor complex: Mom22 is essential for cell viability and directly interacts with preproteins.

A Hönlinger 1, M Kübrich 1, M Moczko 1, F Gärtner 1, L Mallet 1, F Bussereau 1, C Eckerskorn 1, F Lottspeich 1, K Dietmeier 1, M Jacquet 1, et al.
PMCID: PMC230572  PMID: 7760834

Abstract

A multisubunit complex in the mitochondrial outer membrane is responsible for targeting and membrane translocation of nuclear-encoded preproteins. This receptor complex contains two import receptors, a general insertion pore and the protein Mom22. It was unknown if Mom22 directly interacts with preproteins, and two views existed about the possible functions of Mom22: a central role in transfer of preproteins from both receptors to the general insertion pore or a more limited function dependent on the presence of the receptor Mom19. For this report, we identified and cloned Saccharomyces cerevisiae MOM22 and investigated whether it plays a direct role in targeting of preproteins. A preprotein accumulated at the mitochondrial outer membrane was cross-linked to Mom22. The cross-linking depended on the import stage of the preprotein. Overexpression of Mom22 suppressed the respiratory defect of yeast cells lacking Mom19 and increased preprotein import into mom19 delta mitochondria, demonstrating that Mom22 can function independently of Mom19. Overexpression of Mom22 even suppressed the lethal phenotype of a double deletion of the two import receptors known so far (mom19 delta mom72 delta). Deletion of the MOM22 gene was lethal for yeast cells, identifying Mom22 as one of the few mitochondrial membrane proteins essential for fermentative growth. These results suggest that Mom22 plays an essential role in the mitochondrial receptor complex. It directly interacts with preproteins in transit and can perform receptor-like activities.

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Selected References

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  1. Alam R., Hachiya N., Sakaguchi M., Kawabata S., Iwanaga S., Kitajima M., Mihara K., Omura T. cDNA cloning and characterization of mitochondrial import stimulation factor (MSF) purified from rat liver cytosol. J Biochem. 1994 Aug;116(2):416–425. doi: 10.1093/oxfordjournals.jbchem.a124541. [DOI] [PubMed] [Google Scholar]
  2. Baker K. P., Schaniel A., Vestweber D., Schatz G. A yeast mitochondrial outer membrane protein essential for protein import and cell viability. Nature. 1990 Dec 13;348(6302):605–609. doi: 10.1038/348605a0. [DOI] [PubMed] [Google Scholar]
  3. Baker K. P., Schatz G. Mitochondrial proteins essential for viability mediate protein import into yeast mitochondria. Nature. 1991 Jan 17;349(6306):205–208. doi: 10.1038/349205a0. [DOI] [PubMed] [Google Scholar]
  4. Baudin A., Ozier-Kalogeropoulos O., Denouel A., Lacroute F., Cullin C. A simple and efficient method for direct gene deletion in Saccharomyces cerevisiae. Nucleic Acids Res. 1993 Jul 11;21(14):3329–3330. doi: 10.1093/nar/21.14.3329. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Blom J., Kübrich M., Rassow J., Voos W., Dekker P. J., Maarse A. C., Meijer M., Pfanner N. The essential yeast protein MIM44 (encoded by MPI1) is involved in an early step of preprotein translocation across the mitochondrial inner membrane. Mol Cell Biol. 1993 Dec;13(12):7364–7371. doi: 10.1128/mcb.13.12.7364. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Bolliger L., Deloche O., Glick B. S., Georgopoulos C., Jenö P., Kronidou N., Horst M., Morishima N., Schatz G. A mitochondrial homolog of bacterial GrpE interacts with mitochondrial hsp70 and is essential for viability. EMBO J. 1994 Apr 15;13(8):1998–2006. doi: 10.1002/j.1460-2075.1994.tb06469.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Brink S., Flügge U. I., Chaumont F., Boutry M., Emmermann M., Schmitz U., Becker K., Pfanner N. Preproteins of chloroplast envelope inner membrane contain targeting information for receptor-dependent import into fungal mitochondria. J Biol Chem. 1994 Jun 10;269(23):16478–16485. [PubMed] [Google Scholar]
  8. Cheng M. Y., Hartl F. U., Martin J., Pollock R. A., Kalousek F., Neupert W., Hallberg E. M., Hallberg R. L., Horwich A. L. Mitochondrial heat-shock protein hsp60 is essential for assembly of proteins imported into yeast mitochondria. Nature. 1989 Feb 16;337(6208):620–625. doi: 10.1038/337620a0. [DOI] [PubMed] [Google Scholar]
  9. Craig E. A., Kramer J., Kosic-Smithers J. SSC1, a member of the 70-kDa heat shock protein multigene family of Saccharomyces cerevisiae, is essential for growth. Proc Natl Acad Sci U S A. 1987 Jun;84(12):4156–4160. doi: 10.1073/pnas.84.12.4156. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Craig E. A., Kramer J., Shilling J., Werner-Washburne M., Holmes S., Kosic-Smithers J., Nicolet C. M. SSC1, an essential member of the yeast HSP70 multigene family, encodes a mitochondrial protein. Mol Cell Biol. 1989 Jul;9(7):3000–3008. doi: 10.1128/mcb.9.7.3000. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. Daum G., Böhni P. C., Schatz G. Import of proteins into mitochondria. Cytochrome b2 and cytochrome c peroxidase are located in the intermembrane space of yeast mitochondria. J Biol Chem. 1982 Nov 10;257(21):13028–13033. [PubMed] [Google Scholar]
  12. Dekker P. J., Keil P., Rassow J., Maarse A. C., Pfanner N., Meijer M. Identification of MIM23, a putative component of the protein import machinery of the mitochondrial inner membrane. FEBS Lett. 1993 Sep 6;330(1):66–70. doi: 10.1016/0014-5793(93)80921-g. [DOI] [PubMed] [Google Scholar]
  13. Démolis N., Mallet L., Bussereau F., Jacquet M. Improved strategy for large-scale DNA sequencing using DNaseI cleavage for generating random subclones. Biotechniques. 1995 Mar;18(3):453–457. [PubMed] [Google Scholar]
  14. Eckerskorn C., Mewes W., Goretzki H., Lottspeich F. A new siliconized-glass fiber as support for protein-chemical analysis of electroblotted proteins. Eur J Biochem. 1988 Oct 1;176(3):509–519. doi: 10.1111/j.1432-1033.1988.tb14308.x. [DOI] [PubMed] [Google Scholar]
  15. Emtage J. L., Jensen R. E. MAS6 encodes an essential inner membrane component of the yeast mitochondrial protein import pathway. J Cell Biol. 1993 Sep;122(5):1003–1012. doi: 10.1083/jcb.122.5.1003. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Gambill B. D., Voos W., Kang P. J., Miao B., Langer T., Craig E. A., Pfanner N. A dual role for mitochondrial heat shock protein 70 in membrane translocation of preproteins. J Cell Biol. 1993 Oct;123(1):109–117. doi: 10.1083/jcb.123.1.109. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Harkness T. A., Nargang F. E., van der Klei I., Neupert W., Lill R. A crucial role of the mitochondrial protein import receptor MOM19 for the biogenesis of mitochondria. J Cell Biol. 1994 Mar;124(5):637–648. doi: 10.1083/jcb.124.5.637. [DOI] [PMC free article] [PubMed] [Google Scholar]
  18. Hartl F. U., Neupert W. Protein sorting to mitochondria: evolutionary conservations of folding and assembly. Science. 1990 Feb 23;247(4945):930–938. doi: 10.1126/science.2406905. [DOI] [PubMed] [Google Scholar]
  19. Hartl F. U., Ostermann J., Guiard B., Neupert W. Successive translocation into and out of the mitochondrial matrix: targeting of proteins to the intermembrane space by a bipartite signal peptide. Cell. 1987 Dec 24;51(6):1027–1037. doi: 10.1016/0092-8674(87)90589-7. [DOI] [PubMed] [Google Scholar]
  20. Hawlitschek G., Schneider H., Schmidt B., Tropschug M., Hartl F. U., Neupert W. Mitochondrial protein import: identification of processing peptidase and of PEP, a processing enhancing protein. Cell. 1988 Jun 3;53(5):795–806. doi: 10.1016/0092-8674(88)90096-7. [DOI] [PubMed] [Google Scholar]
  21. Hines V., Brandt A., Griffiths G., Horstmann H., Brütsch H., Schatz G. Protein import into yeast mitochondria is accelerated by the outer membrane protein MAS70. EMBO J. 1990 Oct;9(10):3191–3200. doi: 10.1002/j.1460-2075.1990.tb07517.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Horst M., Jenö P., Kronidou N. G., Bolliger L., Oppliger W., Scherer P., Manning-Krieg U., Jascur T., Schatz G. Protein import into yeast mitochondria: the inner membrane import site protein ISP45 is the MPI1 gene product. EMBO J. 1993 Aug;12(8):3035–3041. doi: 10.1002/j.1460-2075.1993.tb05972.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Horwich A. Protein import into mitochondria and peroxisomes. Curr Opin Cell Biol. 1990 Aug;2(4):625–633. doi: 10.1016/0955-0674(90)90103-l. [DOI] [PubMed] [Google Scholar]
  24. Ikeda E., Yoshida S., Mitsuzawa H., Uno I., Toh-e A. YGE1 is a yeast homologue of Escherichia coli grpE and is required for maintenance of mitochondrial functions. FEBS Lett. 1994 Feb 21;339(3):265–268. doi: 10.1016/0014-5793(94)80428-1. [DOI] [PubMed] [Google Scholar]
  25. Jensen R. E., Yaffe M. P. Import of proteins into yeast mitochondria: the nuclear MAS2 gene encodes a component of the processing protease that is homologous to the MAS1-encoded subunit. EMBO J. 1988 Dec 1;7(12):3863–3871. doi: 10.1002/j.1460-2075.1988.tb03272.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  26. Kassenbrock C. K., Cao W., Douglas M. G. Genetic and biochemical characterization of ISP6, a small mitochondrial outer membrane protein associated with the protein translocation complex. EMBO J. 1993 Aug;12(8):3023–3034. doi: 10.1002/j.1460-2075.1993.tb05971.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Keil P., Pfanner N. Insertion of MOM22 into the mitochondrial outer membrane strictly depends on surface receptors. FEBS Lett. 1993 Apr 26;321(2-3):197–200. doi: 10.1016/0014-5793(93)80107-6. [DOI] [PubMed] [Google Scholar]
  28. Kiebler M., Keil P., Schneider H., van der Klei I. J., Pfanner N., Neupert W. The mitochondrial receptor complex: a central role of MOM22 in mediating preprotein transfer from receptors to the general insertion pore. Cell. 1993 Aug 13;74(3):483–492. doi: 10.1016/0092-8674(93)80050-o. [DOI] [PubMed] [Google Scholar]
  29. Kiebler M., Pfaller R., Söllner T., Griffiths G., Horstmann H., Pfanner N., Neupert W. Identification of a mitochondrial receptor complex required for recognition and membrane insertion of precursor proteins. Nature. 1990 Dec 13;348(6302):610–616. doi: 10.1038/348610a0. [DOI] [PubMed] [Google Scholar]
  30. Kübrich M., Keil P., Rassow J., Dekker P. J., Blom J., Meijer M., Pfanner N. The polytopic mitochondrial inner membrane proteins MIM17 and MIM23 operate at the same preprotein import site. FEBS Lett. 1994 Aug 1;349(2):222–228. doi: 10.1016/0014-5793(94)00670-9. [DOI] [PubMed] [Google Scholar]
  31. Laloraya S., Gambill B. D., Craig E. A. A role for a eukaryotic GrpE-related protein, Mge1p, in protein translocation. Proc Natl Acad Sci U S A. 1994 Jul 5;91(14):6481–6485. doi: 10.1073/pnas.91.14.6481. [DOI] [PMC free article] [PubMed] [Google Scholar]
  32. Lithgow T., Junne T., Wachter C., Schatz G. Yeast mitochondria lacking the two import receptors Mas20p and Mas70p can efficiently and specifically import precursor proteins. J Biol Chem. 1994 May 27;269(21):15325–15330. [PubMed] [Google Scholar]
  33. Mallet L., Bussereau F., Jacquet M. Nucleotide sequence analysis of an 11.7 kb fragment of yeast chromosome II including BEM1, a new gene of the WD-40 repeat family and a new member of the KRE2/MNT1 family. Yeast. 1994 Jun;10(6):819–831. doi: 10.1002/yea.320100612. [DOI] [PubMed] [Google Scholar]
  34. Moczko M., Dietmeier K., Söllner T., Segui B., Steger H. F., Neupert W., Pfanner N. Identification of the mitochondrial receptor complex in Saccharomyces cerevisiae. FEBS Lett. 1992 Oct 5;310(3):265–268. doi: 10.1016/0014-5793(92)81345-m. [DOI] [PubMed] [Google Scholar]
  35. Moczko M., Ehmann B., Gärtner F., Hönlinger A., Schäfer E., Pfanner N. Deletion of the receptor MOM19 strongly impairs import of cleavable preproteins into Saccharomyces cerevisiae mitochondria. J Biol Chem. 1994 Mar 25;269(12):9045–9051. [PubMed] [Google Scholar]
  36. Moczko M., Gärtner F., Pfanner N. The protein import receptor MOM19 of yeast mitochondria. FEBS Lett. 1993 Jul 12;326(1-3):251–254. doi: 10.1016/0014-5793(93)81801-6. [DOI] [PubMed] [Google Scholar]
  37. Niidome T., Kitada S., Shimokata K., Ogishima T., Ito A. Arginine residues in the extension peptide are required for cleavage of a precursor by mitochondrial processing peptidase. Demonstration using synthetic peptide as a substrate. J Biol Chem. 1994 Oct 7;269(40):24719–24722. [PubMed] [Google Scholar]
  38. Ou W. J., Kumamoto T., Mihara K., Kitada S., Niidome T., Ito A., Omura T. Structural requirement for recognition of the precursor proteins by the mitochondrial processing peptidase. J Biol Chem. 1994 Oct 7;269(40):24673–24678. [PubMed] [Google Scholar]
  39. Pfanner N., Craig E. A., Meijer M. The protein import machinery of the mitochondrial inner membrane. Trends Biochem Sci. 1994 Sep;19(9):368–372. doi: 10.1016/0968-0004(94)90113-9. [DOI] [PubMed] [Google Scholar]
  40. Pollock R. A., Hartl F. U., Cheng M. Y., Ostermann J., Horwich A., Neupert W. The processing peptidase of yeast mitochondria: the two co-operating components MPP and PEP are structurally related. EMBO J. 1988 Nov;7(11):3493–3500. doi: 10.1002/j.1460-2075.1988.tb03225.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  41. Ramage L., Junne T., Hahne K., Lithgow T., Schatz G. Functional cooperation of mitochondrial protein import receptors in yeast. EMBO J. 1993 Nov;12(11):4115–4123. doi: 10.1002/j.1460-2075.1993.tb06095.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  42. Ryan K. R., Jensen R. E. Mas6p can be cross-linked to an arrested precursor and interacts with other proteins during mitochondrial protein import. J Biol Chem. 1993 Nov 15;268(32):23743–23746. [PubMed] [Google Scholar]
  43. Schena M., Picard D., Yamamoto K. R. Vectors for constitutive and inducible gene expression in yeast. Methods Enzymol. 1991;194:389–398. doi: 10.1016/0076-6879(91)94029-c. [DOI] [PubMed] [Google Scholar]
  44. Scherer P. E., Manning-Krieg U. C., Jenö P., Schatz G., Horst M. Identification of a 45-kDa protein at the protein import site of the yeast mitochondrial inner membrane. Proc Natl Acad Sci U S A. 1992 Dec 15;89(24):11930–11934. doi: 10.1073/pnas.89.24.11930. [DOI] [PMC free article] [PubMed] [Google Scholar]
  45. Schlossmann J., Dietmeier K., Pfanner N., Neupert W. Specific recognition of mitochondrial preproteins by the cytosolic domain of the import receptor MOM72. J Biol Chem. 1994 Apr 22;269(16):11893–11901. [PubMed] [Google Scholar]
  46. Sharp P. M., Li W. H. The codon Adaptation Index--a measure of directional synonymous codon usage bias, and its potential applications. Nucleic Acids Res. 1987 Feb 11;15(3):1281–1295. doi: 10.1093/nar/15.3.1281. [DOI] [PMC free article] [PubMed] [Google Scholar]
  47. Sikorski R. S., Hieter P. A system of shuttle vectors and yeast host strains designed for efficient manipulation of DNA in Saccharomyces cerevisiae. Genetics. 1989 May;122(1):19–27. doi: 10.1093/genetics/122.1.19. [DOI] [PMC free article] [PubMed] [Google Scholar]
  48. Steger H. F., Söllner T., Kiebler M., Dietmeier K. A., Pfaller R., Trülzsch K. S., Tropschug M., Neupert W., Pfanner N. Import of ADP/ATP carrier into mitochondria: two receptors act in parallel. J Cell Biol. 1990 Dec;111(6 Pt 1):2353–2363. doi: 10.1083/jcb.111.6.2353. [DOI] [PMC free article] [PubMed] [Google Scholar]
  49. Söllner T., Griffiths G., Pfaller R., Pfanner N., Neupert W. MOM19, an import receptor for mitochondrial precursor proteins. Cell. 1989 Dec 22;59(6):1061–1070. doi: 10.1016/0092-8674(89)90762-9. [DOI] [PubMed] [Google Scholar]
  50. Söllner T., Pfaller R., Griffiths G., Pfanner N., Neupert W. A mitochondrial import receptor for the ADP/ATP carrier. Cell. 1990 Jul 13;62(1):107–115. doi: 10.1016/0092-8674(90)90244-9. [DOI] [PubMed] [Google Scholar]
  51. Söllner T., Rassow J., Pfanner N. Analysis of mitochondrial protein import using translocation intermediates and specific antibodies. Methods Cell Biol. 1991;34:345–358. doi: 10.1016/s0091-679x(08)61689-1. [DOI] [PubMed] [Google Scholar]
  52. Söllner T., Rassow J., Wiedmann M., Schlossmann J., Keil P., Neupert W., Pfanner N. Mapping of the protein import machinery in the mitochondrial outer membrane by crosslinking of translocation intermediates. Nature. 1992 Jan 2;355(6355):84–87. doi: 10.1038/355084a0. [DOI] [PubMed] [Google Scholar]
  53. Witte C., Jensen R. E., Yaffe M. P., Schatz G. MAS1, a gene essential for yeast mitochondrial assembly, encodes a subunit of the mitochondrial processing protease. EMBO J. 1988 May;7(5):1439–1447. doi: 10.1002/j.1460-2075.1988.tb02961.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
  54. von Heijne G., Steppuhn J., Herrmann R. G. Domain structure of mitochondrial and chloroplast targeting peptides. Eur J Biochem. 1989 Apr 1;180(3):535–545. doi: 10.1111/j.1432-1033.1989.tb14679.x. [DOI] [PubMed] [Google Scholar]

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