, Volume 46, Issue 2, pp 146–153 | Cite as

The biogenesis and function of eukaryotic porins

  • M. Dihanich
Multi-author Review


Like most other mitochondrial proteins porin is synthesized in the cytosol and imported posttranslationally into the outer mitochondrial membrane. This transport follows the general rules for mitochondrial, protein import with a few aberrations: a) porin contains an,uncleaved NH2-terminal signal sequence, b) also its carboxyterminus might be involved in the import process, and c) this transport does not seem to require a membrane potential Δψ, although it is ATP-dependent. Most likely the actual import step occurs at contact sites between the outer and the inner mitochondrial membrane and involved at least one receptor protein.

Although porin is known to be the major gate through the outer mitochondrial membrane, its absence only causes transient respiratory problems in yeast cells. This could mean a) that there is a bypass for some mitochondrial functions in the cytosol and/or b) that there are alternative channel proteins in the outer membrane. The first idea is supported by the overexpression of cytosolic virus-like particles in yeast cells lacking porin and the second by the occurrence of residual pore activity in mitochondrial outer membrane purified from porinless mutant cells.

Key words

Mitochondria outer membrane porin transport signal sequence contact sites deletion mutant virus-like particle 


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  1. 1.
    Benz, R., Porin from bacterial and mitochondrial outer membranes. CRC Cr. Rev. Biochem.19 (1985) 145–190.Google Scholar
  2. 2.
    Benz, R., Ludwig, O., de Pinto, V., and Palmieri, F., Permeability properties of mitochondrial porins of different eukaryotic cells, in: Achievements and Perspectives of Mitochondrial Research, vol. 1: Bioenergetics, pp. 317–327. Eds E. Quagliariello et al. Elsevier Science Publishers B.V. (Biomedical Division), Amsterdam 1985.Google Scholar
  3. 3.
    Chen, W.J., and Douglas, M., The role of protein structure in the mitochondrial import pathway: unfolding of mitochondrially bound precursors is required for membrane translocation. J. biol. Chem.262 (1987) 15605–15609.PubMedGoogle Scholar
  4. 4.
    Chirico, W. J., Waters, M. G., and Blobel, G., 70 k heat shock related proteins stimulate protein translocation into microsomes. Nature332 (1988) 805–810.PubMedGoogle Scholar
  5. 5.
    Colombini, M., A candidate for the permeability pathway of the outer mitochondrial membrane. Nature279 (1979) 643–645.PubMedGoogle Scholar
  6. 6.
    Colombini, M., Pore size and properties of channels from mitochondria isolated fromNeurospora crassa. J. Membr. Biol.53 (1980) 79–84.Google Scholar
  7. 7.
    Deisenhofer, J., Epp, O., Miki, K., Huber R., and Michel, H., Structure of the protein subunits in the photosynthetic reaction centre ofRhodopseudomonas viridis at 3A resolution. Nature318 (1985) 618–624.Google Scholar
  8. 8.
    Deshaies, R. J., Koch, B. D., and Schekman, R., The role of stress proteins in membrane biogenesis. TIBS13 (1988) 384–388.PubMedGoogle Scholar
  9. 9.
    Deshaies, R. J., Koch, B. D., Werner-Washburne, M., Craig, E. A., and Schekman, R., A subfamily of stress proteins facilitates translocation of secretory and mitochondrial precursor polypeptides. Nature332 (1988) 800–805.PubMedGoogle Scholar
  10. 10.
    Dihanich, M., Schmid, A., Oppliger W., and Benz, R., Identification of a new pore in the mitochondrial outer membrane of a porin deficient yeast mutant. Eur. J. Biochem.181 (1989) 703–708.PubMedGoogle Scholar
  11. 11.
    Dihanich, M., Suda, K., and Schatz, G., A yeast mutant lacking mitochondrial porin is respiratory-deficient but can recover respiration with simultaneous accumulation of an 86-kd extramitochondrial protein. EMBO J.6 (1987) 723–728.PubMedGoogle Scholar
  12. 12.
    Dihanich, M., Van Tuinen, E., Lambris, J. D., and Marshallsay, B., Accumulation of viruslike particles in a yeast mutant lacking a mitochondrial pore protein. Molec. Cell. Biol.9 (1989) 1100–1108.PubMedGoogle Scholar
  13. 13.
    Eilers, M., Hwang, S., and Schatz, G., Unfolding and refolding of a purified precursor protein during import into isolated mitochondria. EMBO J.7 (1988) 1139–1145.PubMedGoogle Scholar
  14. 14.
    Eilers, M., Oppliger, W., and Schatz, G., Both ATP and an energized inner membrane are required to import a purified precursor protein into mitochondria. EMBO J.6 (1987) 1073–1077.PubMedGoogle Scholar
  15. 15.
    Eilers, M., and Schatz, G., Binding of a specific ligand inhibits import of a purified precursor protein into mitochondria Nature322 (1986) 228–232.PubMedGoogle Scholar
  16. 16.
    Eilers, M., and Schatz, G., Protein unfolding and the energetics of protein translocation across biological membranes. Cell52 (1988) 481–483.PubMedGoogle Scholar
  17. 17.
    Freitag, H., Janes, M., and Neupert, W., Biosynthesis of mitochondrial porin and insertion into the mitochondrial membrane ofNeurospora crassa. Eur. J. Biochem.126 (1982) 197–202.PubMedGoogle Scholar
  18. 18.
    Freitag, H., Neupert, W., and Benz, R., Purification and characterization of a pore protein of the outer mitochondrial membrane fromNeurospora crassa. Eur. J. Biochem.123 (1982) 629–636.PubMedGoogle Scholar
  19. 19.
    Garoff, H., Using recombinant DNA techniques to study protein targeting in the eukaryotic cell. A. Rev. Cell Biol.1 (1985) 403–445.Google Scholar
  20. 20.
    Gasser, S., Daum, G., and Schatz, G., Import of proteins into mitochondria: energy-dependent uptake of precursors by isolated mitochondria. J. biol. Chem.257 (1982), 13034–13041.PubMedGoogle Scholar
  21. 21.
    Gasser, S., and Schatz, G., Import of proteins into mitochondria:in vitro studies on the biogenesis of the outer membrane. J. biol. Chem.258 (1983) 3427–3430.PubMedGoogle Scholar
  22. 22.
    Hamajima, S., Sakaguchi, M., Mihara, K., Ono, S., and Sato, R., Both amino-and carboxy-terminal portions are required for insertion of porin into the outer mitochondrial membrane. J. Biochem.104 (1988) 362–367.PubMedGoogle Scholar
  23. 23.
    Hase, T., Müller, U., Riezman, H., and Schatz, G., A 70-kd protein of the yeast mitochondrial outer membrane is targeted and anchored via its extreme amino terminus. EMBO J.3 (1984) 3157–3164.PubMedGoogle Scholar
  24. 24.
    Hase, T., Riezman, H., Suda, K., and Schatz, G., Import of proteins into mitochondria: nucleotide sequence of the gene for a 70-kd protein of the yeast mitochondrial outer membrane. EMBO J.2 (1983) 2169–2172.PubMedGoogle Scholar
  25. 25.
    Hay, R., Boehni, P., and Gasser, S., How mitochondria import proteins. Biochim. biophys. Acta779 (1984) 65–87.PubMedGoogle Scholar
  26. 26.
    Hurt, E. C., Unravelling the role of ATP in posttranslational protein translocation. TIBS12 (1987) 369–370.Google Scholar
  27. 27.
    Hurt, E. C., Müller, U., and Schatz, G., The first twelve amino acids of a yeast mitochondrial outer, membrane protein can direct a nuclear-encoded cytochrome oxidase subunit to the mitochondrial inner membrane. EMBO J.4 (1985a) 3509–3518.PubMedGoogle Scholar
  28. 28.
    Hurt, E.C., Pesold-Hurt, B., Suda, S., Oppliger, W., and Schatz, G., The first twelve amino acids (less than half of the pre-sequence) of an imported mitochondrial protein can direct mouse cytosolic dihydrofolate reductase into the yeast mitochondrial matrix. EMBO J.4 (1985b) 2061–2068.PubMedGoogle Scholar
  29. 29.
    Keng, T., Alani, E., and Guarente, L., The nine amino-terminal residues of δ-aminolevulinate synthase direct β-galactosidase into the mitochondrial matrix. Molec. cell. Biol.6 (1986) 355–364.PubMedGoogle Scholar
  30. 30.
    Kleene, R., Pfanner, N., Pfaller, R., Link, T.A., Sebald, W., Neupert, W., and Tropschug, M., Mitochondrial porin ofNeurospora crassa: cDNA cloning, in vitro expression and import into mitochondria. EMBO J.6 (1987) 2627–2633.PubMedGoogle Scholar
  31. 31.
    Linden, M., Gellerfors, P., and Nelson, B.D., Purification of a protein having pore forming activity from the rat liver mitochondrial outer membrane. Biochem. J.208 (1982) 77–82.PubMedGoogle Scholar
  32. 32.
    Maccechini M.-L., Rudin, Y., Blobel, G., and Schatz, G., Import of proteins into mitochondria: precursor forms of the extramitochondrially made F1-ATPase subunits in yeast. Proc. natl Acad. Sci. USA76 (1979) 343–347.PubMedGoogle Scholar
  33. 33.
    Malamed, S., and Recknagel, R.O., The osmotic behavior of the sucrose-inaccessible space of mitochondrial pellets from rat liver. J. biol. Chem.234 (1959) 3027–3030.PubMedGoogle Scholar
  34. 33a.
    Michejda, J., Guo, X.J., and Lauquin, G.J.M., Bioenergetic consequences of the lack of mitochondrial porin: identification of a putative new pore, in: Anion Carriers of Mitochondrial Membranes, pp. 225–235. Eds A. Azzi et al. Springer, Heidelberg/New York 1989.Google Scholar
  35. 34.
    Mihara, K., Blobel, G., and Sato, R., In vitro synthesis and integration into mitochondria of porin, a major protein of the outer mitochondrial membrane ofSaccharomyces cerevisiae. Proc. natl Acad. Sci. USA79 (1982) 7102–7106.PubMedGoogle Scholar
  36. 35.
    Mihara, K., and Sato, R., Molecular cloning and sequencing of cDNA for yeast porin, an outer mitochondrial membrane protein: a search for targeting signal in the primary structure. EMBO J.4 (1985) 769–774.PubMedGoogle Scholar
  37. 36.
    Müller, G., and Zimmermann, R., Import of honeybee prepromelittin into the endoplasmic reticulum: energy requirements for membrane insertion. EMBO J.7 (1988) 639–648.PubMedGoogle Scholar
  38. 37.
    Nguyen, M., Bell, A.W., and Shore, G.W., Protein sorting between mitochondrial membranes specified by position of the stop-transfer domain. J. Cell Biol.106 (1988) 1499–1505.PubMedGoogle Scholar
  39. 38.
    O'Brien, R.L., and Brierly, G., Compartmentation of Heart Mitochondria. I. Permeability characteristics of isolated beef heart mitochondria. J. biol. Chem.240 (1965) 4527–4531.PubMedGoogle Scholar
  40. 39.
    Ohba, M., and Schatz, G., Protein import into yeast mitochondria is inhibited by antibodies raised against 45-kd proteins of the outer membrane. EMBO J.6 (1987a) 2109–2115.PubMedGoogle Scholar
  41. 40.
    Ohba, M., and Schatz, G., Disruption of the outer membrane restores protein import to trypsin-treated yeast mitochondria. EMBO J.6 (1987b) 2117–2122.PubMedGoogle Scholar
  42. 41.
    Ono, H., and Tuboi, S., Integration of porin synthesized in vitro into outer mitochondrial membranes. Eur. J. Biochem.168 (1987) 509–514.PubMedGoogle Scholar
  43. 42.
    Park, S., Liu, G., Topping, T.B., Cover, W.H., and Randall, L.L., Modulation of the folding pathways of exported proteins by the leader sequence. Science239 (1988) 1033–1035.PubMedGoogle Scholar
  44. 43.
    Pfaller, R., Freitag, H., Harmey, M.A., Benz, R., and Neupert, W., A water-soluble from of porin from the mitochondrial outer membrane ofNeurospora crassa. J. biol. Chem.260 (1985) 8188–8193.PubMedGoogle Scholar
  45. 44.
    Pfaller, R., and Neupert, W., High-affinity binding sites involved in the import of porin into mitochondria. EMBO J.6 (1987) 2635–2642.PubMedGoogle Scholar
  46. 45.
    Pfaller, R., Steger, H.F., Rassow, J., Pfanner, N., and Neupert, W., Import pathways of precursor proteins into mitochondria: multiple receptor sites are followed by a common membrane insertion site. J. Cell Biol.107 (1983) 2483–2490.Google Scholar
  47. 46.
    Pfanner, N., Hartl, F.-U., Guiard, B., and Neupert, W., Mitochondrial precursor proteins are imported through a hydrophilic membrane environment. Eur. J. Biochem.169 (1987) 289–293.PubMedGoogle Scholar
  48. 47.
    Pfanner, N., and Neupert, W., Transport of proteins into mitochondria: a potassium diffusion potential is able to drive the import of ADP/ATP carrier. EMBO J.4 (1985) 2819–2825PubMedGoogle Scholar
  49. 48.
    Pfanner, N., Pfaller, R., Kleene, R., Ito, M., Tropschug, M., and Neupert, W., Role of ATP in mitochondrial protein import: conformational alteration of a precursor protein can substitute for ATP requirement. J. biol. Chem.263 (1988) 4049–4051.PubMedGoogle Scholar
  50. 49.
    Pfanner, N., Tropschug, M., and Neupert, W., Mitochondrial protein import: nucleoside triphosphates are involved in conferring importcompetence to precursors. Cell49 (1987) 815–823.PubMedGoogle Scholar
  51. 50.
    Pietras, D.F., Diamond, M.E., and Bruenn, J.A., Identification of a putative RNA dependent RNA polymerase encoded by a yeast double stranded RNA virus. Nucl. Acid Res.16 (1988) 6225.Google Scholar
  52. 51.
    Randall, L.L., and Hardy, S.J.S., Correlation of competence for export within lack of tertiary structure of the mature species: a studyin vivo of maltose-binding protein inE. coli. Cell46 (1986) 921–928.PubMedGoogle Scholar
  53. 52.
    Riezman, H., Hase, T., van Loon, A.P.G.M., Grivell, L.A., Suda, K., and Schatz, G., Import of proteins into mitochondria: a 70 kilodalton outer membrane protein with a large carboxy-terminal deletion is still transported to the outer membrane. EMBO J.2 (1983c) 2161–2168.PubMedGoogle Scholar
  54. 53.
    Riezmann, H., Hay, R., Gasser S., Daum, G., Schneider G., Witte, C., and Schatz, G., The outer membrane of yeast mitochondria: isolation of outside-out sealed vesicles. EMBO J.2 (1983a) 1105–1111.Google Scholar
  55. 54.
    Riezman, H., Hay, R., Witte, C., Nelson, N., and Schatz, G., Yest mitochondrial outer membrane specifically binds cytoplasmically synthesized precursors of mitochondrial proteins. EMBO J.2 (1983b) 1113–1118.Google Scholar
  56. 55.
    Roise, D., Theiler, F., Horvath, S.J., Tomich, J.M., Richards, J.H., Allison, D.S., and Schatz, G., Amphiphilicity is essential for mitochondrial presequence function. EMBO J.7 (1988) 649–653.PubMedGoogle Scholar
  57. 56.
    Roos, N., Benz, R., and Brdiczka, D., Identification and characterization of the pore-forming protein in the outer membrane of rat liver mitochondria. Biochim. biophys. Acta686 (1982) 204–214.PubMedGoogle Scholar
  58. 57.
    Schatz, G., How mitochondria import proteins from the cytoplasm. FEBS Lett.103 (1979) 203–211.PubMedGoogle Scholar
  59. 58.
    Schatz, G., 17th Sir Hans Krebs Lecture: Signals guiding proteins to their correct locations in mitochondria. Eur. J. Biochem.165 (1987) 1–6.PubMedGoogle Scholar
  60. 59.
    Schein, S.J., Colombini, M., and Finkelstein, A., Reconstitution in planar lipid bilayers of a voltage-dependent anion-selective channel obtained from Paramecium mitochondria. J. Membr. Biol.30 (1976) 99–120.PubMedGoogle Scholar
  61. 60.
    Schleyer, M., and Neupert, W., Transport of proteins into mitochondria: translocational intermediates spanning contact sites between outer and inner membranes. Cell43 (1985) 339–350.PubMedGoogle Scholar
  62. 61.
    Schleyer, M., Schmidt, B., and Neupert, W., Requirements of a membrane potential for the posttranslational transfer of proteins in mitochondria. Eur. J. Biochem.125 (1982) 109–116.PubMedGoogle Scholar
  63. 62.
    Suissa, M., Suda, K., and Schatz, G., Isolation of the nuclear yeast genes for citrate synthase and fifteen other mitochondrial proteins by a new screening method. EMBO J.3 (1984) 1773–1781.PubMedGoogle Scholar
  64. 63.
    Teintze, M., and Neupert, W., Biosynthesis and assembly of mitochondrial proteins, in: Cell Membranes: Methods and Reviews, vol. 1, pp. 89–114. Eds E. Elson, W. Frazier and L. Glaser. Plenum Press, New York 1984.Google Scholar
  65. 64.
    Tipper, D.J., and Bostian, K.A., Double-stranded ribonucleic acid killer systems in yeasts. Microbiol. Rev.48 (1984) 125–156.PubMedGoogle Scholar
  66. 65.
    Tzagoloff, A., Mitochondria. Ed. P. Siekevitz, Plenum Press, New York 1982.Google Scholar
  67. 66.
    van Loon, A.P.G.M., Brändli, A.W., Pesold-Hurt, B., Blank, D., and Schatz, G., Transport of proteins to the mitochondrial intermembrane space: the ‘matrix-targeting’ and the ‘sorting’ domains in the cytochrome c1 presequence. EMBO J.6 (1987) 2433–2439.PubMedGoogle Scholar
  68. 67.
    Verner, K., and Lemire, B., Tight folding of a passenger protein can interfere with the targeting function of a mitochondrial presequence. EMBO J.8 (1989) 1491–1495.PubMedGoogle Scholar
  69. 68.
    Verner, K., and Schatz, G., Import of an incompletely folded precursor protein into isolated mitochondria requires an energized inner membrane, but no added ATP. EMBO J.6 (1987) 2449–2456.PubMedGoogle Scholar
  70. 69.
    Verner, K., and Schatz, G., Protein translocation across membranes. Science241 (1988) 1307–1313.PubMedGoogle Scholar
  71. 70.
    Vestweber, D., and Schatz, G., A chimeric mitochondrial precursor protein with internal disulfide bridges blocks import of authentic precursors into mitochondria and allows quantitation of import sites. J. Cell Biol.107 (1988a) 2037–2043.PubMedGoogle Scholar
  72. 71.
    Vestweber, D., and Schatz, G., Mitochondria can import artificial precursor proteins containing a branched polypeptide chain or a carboxy-terminal stibene disulfonate. J. Cell Biol.107 (1988b) 2045–2049.PubMedGoogle Scholar
  73. 72.
    Wessels, H.P., and Spiess, M., Insertion of a multi-spanning membrane protein occurs sequentially and requires only one signal sequence. Cell55 (1988) 61–70.PubMedGoogle Scholar
  74. 73.
    Wickner, R.B., Double-stranded RNA replication in yeast: the killer system. A. Rev. Biochem.55 (1986) 373–395.Google Scholar
  75. 74.
    Zalman, L.S., Nikaido, H., and Kagawa, Y., Mitochondrial outer membrane contains a protein producing nonspecific diffusion channels. J. biol. Chem.255 (1980) 1771–1774.PubMedGoogle Scholar
  76. 75.
    Zimmermann, R., Hennig, B., and Neupert, W., Different transport pathways of individual precursor proteins in mitochondria. Eur. J. Biochem.116 (1981) 445–460.Google Scholar
  77. 76.
    Zwizinski, C., Schleyer, M., and Neupert, W., Transfer of proteins into mitochondria: precursor to the ADP/ATP carrier binds to receptor sites on isolated mitochondria. J. biol. Chem.258 (1983) 4071–4074.PubMedGoogle Scholar
  78. 77.
    Zwizinski, C., Schleyer, M., and Neupert, W., Proteinaceous receptors for the import of mitochondrial precursor proteins. J. biol. Chem.259 (1984) 7850–7856.PubMedGoogle Scholar

Copyright information

© Birkhäuser Verlag 1990

Authors and Affiliations

  • M. Dihanich
    • 1
  1. 1.Friedrich-Miescher-Institute(Switzerland)

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