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MscL: channeling membrane tension

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Abstract

Mechanosensitive channels are integral components for the response of bacteria to osmotic shock. The mechanosensitive channel of large conductance (MscL) responds to extreme turgor pressure increase that would otherwise lyse the cellular membrane. MscL has been studied as a model mechanosensitive channel using both structural and functional approaches. We will summarize the structural data and discuss outstanding questions surrounding the gating mechanism of this homo-oligomeric channel that has ~3 nS conductance. Specifically, we will explore the following: (1) the variability in oligomeric state that has been observed, (2) the open pore size measurements, and (3) the role of the C-terminal coiled coil domain for channel function. The oligomeric state of MscL has been characterized using various techniques, with a pentamer being the predominant form; however, the presence of mixtures of oligomers in the membrane is still uncertain. In the absence of structural data for the open state of MscL, the diameter of the open state pore has been estimated by several different approaches, leading to a current estimate between 25 and 30 Å. While the C-terminal domain is highly conserved among MscL homologues, it is not required for activity in vivo or in vitro. This domain is likely to remain intact during the gating transition and perform a filtering function that retains valuable osmolytes in the cytosol. Overall, studies of MscL have provided significant insight to the field, and serve as a paradigm for the analysis of non-homologous, eukaryotic mechanosensitive channel proteins.

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References

  1. Anishkin A, Gendel V, Sharifi NA, Chiang CS, Shirinian L, Guy HR, Sukharev S (2003) On the conformation of the COOH-terminal domain of the large mechanosensitive channel MscL. J Gen Physiol 121:227–244

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  2. Azem A, Shaked I, Rosenbusch JP, Daniel E (1995) Cross-linking of porin with glutardialdehyde: a test for the adequacy of premises of cross-linking theory. Biochim Biophys Acta 1243:151–156

    Article  PubMed  Google Scholar 

  3. Basle A, Iyer R, Delcour AH (2004) Subconductance states in OmpF gating. Biochim Biophys Acta 1664:100–107

    Article  CAS  PubMed  Google Scholar 

  4. Beckstein O, Tai K, Sansom MS (2004) Not ions alone: barriers to ion permeation in nanopores and channels. J Amer Chem Soc 126:14694–14695

    Article  CAS  Google Scholar 

  5. Berrier C, Coulombe A, Houssin C, Ghazi A (1989) A patch-clamp study of ion channels of inner and outer membranes and of contact zones of E. coli, fused into giant liposomes. Pressure-activated channels are localized in the inner membrane. FEBS Lett 259:27–32

    Article  CAS  PubMed  Google Scholar 

  6. Blount P, Sukharev SI, Moe PC, Schroeder MJ, Guy HR, Kung C (1996) Membrane topology and multimeric structure of a mechanosensitive channel protein of Escherichia coli. EMBO J 15:4798–4805

  7. Blount P, Sukharev SI, Schroeder MJ, Nagle SK, Kung C (1996) Single residue substitutions that change the gating properties of a mechanosensitive channel in Escherichia coli. Proc Natl Acad Sci U S A 93:11652–11657

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  8. Booth IR, Louis P (1999) Managing hypoosmotic stress: aquaporins and mechanosensitive channels in Escherichia coli. Curr Opin Microbiol 2:166–169

    Article  CAS  PubMed  Google Scholar 

  9. Bosshard HR, Marti DN, Jelesarov I (2004) Protein stabilization by salt bridges: concepts, experimental approaches and clarification of some misunderstandings. J Mol Recogn 17:1–16

    Article  CAS  Google Scholar 

  10. Chang G, Spencer RH, Lee AT, Barclay MT, Rees DC (1998) Structure of the MscL homolog from Mycobacterium tuberculosis: a gated mechanosensitive ion channel. Science 282:2220–2226

    Article  CAS  PubMed  Google Scholar 

  11. Coste B, Mathur J, Schmidt M, Earley TJ, Ranade S, Petrus MJ, Dubin AE, Patapoutian A (2010) Piezo1 and Piezo2 are essential components of distinct mechanically activated cation channels. Science 330:55–60

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  12. Coste B, Xiao B, Santos JS, Syeda R, Grandl J, Spencer KS, Kim SE, Schmidt M, Mathur J, Dubin AE, Montal M, Patapoutian A (2012) Piezo proteins are pore-forming subunits of mechanically activated channels. Nature 483:176–181

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  13. Cowan SW, Schirmer T, Rummel G, Steiert M, Ghosh R, Pauptit RA, Jansonius JN, Rosenbusch JP (1992) Crystal structures explain functional properties of two E. coli porins. Nature 358:727–733

    Article  CAS  PubMed  Google Scholar 

  14. Cruickshank CC, Minchin RF, Le Dain AC, Martinac B (1997) Estimation of the pore size of the large-conductance mechanosensitive ion channel of Escherichia coli. Biophys J 73:1925–1931

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  15. Dorwart MR, Wray R, Brautigam CA, Jiang Y, Blount P (2010) S. aureus MscL is a pentamer in vivo but of variable stoichiometries in vitro: implications for detergent-solubilized membrane proteins. PLoS Biol 8:e1000555

    Article  PubMed Central  PubMed  Google Scholar 

  16. Folgering JH, Wolters JC, Poolman B (2005) Engineering covalent oligomers of the mechanosensitive channel of large conductance from Escherichia coli with native conductance and gating characteristics. Protein Sci 14:2947–2954

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  17. Gandhi CS, Walton TA, Rees DC (2011) OCAM: a new tool for studying the oligomeric diversity of MscL channels. Protein Sci 20:313–326

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  18. Gunasekar SK, Asnani M, Limbad C, Haghpanah JS, Hom W, Barra H, Nanda S, Lu M, Montclare JK (2009) N-terminal aliphatic residues dictate the structure, stability, assembly, and small molecule binding of the coiled-coil region of cartilage oligomeric matrix protein. Biochemistry 48:8559–8567

    Article  CAS  PubMed  Google Scholar 

  19. Hase CC, Le Dain AC, Martinac B (1995) Purification and functional reconstitution of the recombinant large mechanosensitive ion channel (MscL) of Escherichia coli. J Biol Chem 270:18329–18334

    Article  CAS  PubMed  Google Scholar 

  20. Hase CC, Minchin RF, Kloda A, Martinac B (1997) Cross-linking studies and membrane localization and assembly of radiolabelled large mechanosensitive ion channel (MscL) of Escherichia coli. Biochem Biophys Res Comm 232:777–782

    Article  CAS  PubMed  Google Scholar 

  21. Haswell ES, Meyerowitz EM (2006) MscS-like proteins control plastid size and shape in Arabidopsis thaliana. Curr Biol 16:1–11

    Article  CAS  PubMed  Google Scholar 

  22. Hille B (1968) Pharmacological modifications of the sodium channels of frog nerve. J Gen Physiol 51:199–219

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  23. Iscla I, Wray R, Blount P (2011) The oligomeric state of the truncated mechanosensitive channel of large conductance shows no variance in vivo. Protein Sci 20:1638–1642

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  24. Kung C (2005) A possible unifying principle for mechanosensation. Nature 436:647–654

    Article  CAS  PubMed  Google Scholar 

  25. Kung C, Martinac B, Sukharev S (2010) Mechanosensitive channels in microbes. Ann Rev Microbiol 64:313–329

    Article  CAS  Google Scholar 

  26. LeMasurier M, Heginbotham L, Miller C (2001) KcsA: it's a potassium channel. J Gen Physiol 118:303–314

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  27. Levina N, Totemeyer S, Stokes NR, Louis P, Jones MA, Booth IR (1999) Protection of Escherichia coli cells against extreme turgor by activation of MscS and MscL mechanosensitive channels: identification of genes required for MscS activity. EMBO J 18:1730–1737

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  28. Liu Z, Gandhi CS, Rees DC (2009) Structure of a tetrameric MscL in an expanded intermediate state. Nature 461:120–124

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  29. Malashkevich VN, Kammerer RA, Efimov VP, Schulthess T, Engel J (1996) The crystal structure of a five-stranded coiled coil in COMP: a prototype ion channel? Science 274:761–765

    Article  CAS  PubMed  Google Scholar 

  30. Martinac B, Buechner M, Delcour AH, Adler J, Kung C (1987) Pressure-sensitive ion channel in Escherichia coli. Proc Natl Acad Sci U S A 84:2297–2301

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  31. Maurer JA, Dougherty DA (2003) Generation and evaluation of a large mutational library from the Escherichia coli mechanosensitive channel of large conductance, MscL: implications for channel gating and evolutionary design. J Biol Chem 278:21076–21082

    Article  CAS  PubMed  Google Scholar 

  32. Mika JT, Birkner JP, Poolman B, Kocer A (2013) On the role of individual subunits in MscL gating: "all for one, one for all?". FASEB J 27:882–892

    Article  CAS  PubMed  Google Scholar 

  33. Moe PC, Blount P, Kung C (1998) Functional and structural conservation in the mechanosensitive channel MscL implicates elements crucial for mechanosensation. Mol Microbiol 28:583–592

    Article  CAS  PubMed  Google Scholar 

  34. Ornatska M, Jones SE, Naik RR, Stone MO, Tsukruk VV (2003) Biomolecular stress-sensitive gauges: surface-mediated immobilization of mechanosensitive membrane protein. J Amer Chem Soc 125:12722–12723

    Article  CAS  Google Scholar 

  35. Ou X, Blount P, Hoffman RJ, Kung C (1998) One face of a transmembrane helix is crucial in mechanosensitive channel gating. Proc Natl Acad Sci U S A 95:11471–11475

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  36. Perozo E, Cortes DM, Sompornpisut P, Kloda A, Martinac B (2002) Open channel structure of MscL and the gating mechanism of mechanosensitive channels. Nature 418:942–948

    Article  CAS  PubMed  Google Scholar 

  37. Saint N, Lacapere JJ, Gu LQ, Ghazi A, Martinac B, Rigaud JL (1998) A hexameric transmembrane pore revealed by two-dimensional crystallization of the large mechanosensitive ion channel (MscL) of Escherichia coli. J Biol Chem 273:14667–14670

    Article  CAS  PubMed  Google Scholar 

  38. Schrempf H, Schmidt O, Kummerlen R, Hinnah S, Muller D, Betzler M, Steinkamp T, Wagner R (1995) A prokaryotic potassium ion channel with two predicted transmembrane segments from Streptomyces lividans. EMBO J 14:5170–5178

    CAS  PubMed Central  PubMed  Google Scholar 

  39. Spencer RH, Chang G, Rees DC (1999) 'Feeling the pressure': structural insights into a gated mechanosensitive channel. Curr Opin Struct Biol 9:448–454

    Article  CAS  PubMed  Google Scholar 

  40. Steinbacher S, Bass R, Strop P, Rees DC (2007) Structures of the prokaryotic mechanosensitive channels MscL and MscS. Curr Top Membr 58:1–24

    Article  CAS  Google Scholar 

  41. Sukharev S, Betanzos M, Chiang CS, Guy HR (2001) The gating mechanism of the large mechanosensitive channel MscL. Nature 409:720–724

    Article  CAS  PubMed  Google Scholar 

  42. Sukharev S, Durell SR, Guy HR (2001) Structural models of the MscL gating mechanism. Biophys J 81:917–936

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  43. Sukharev SI, Martinac B, Arshavsky VY, Kung C (1993) Two types of mechanosensitive channels in the Escherichia coli cell envelope: solubilization and functional reconstitution. Biophysical J 65:177–183

    Article  CAS  Google Scholar 

  44. Sukharev SI, Blount P, Martinac B, Blattner FR, Kung C (1994) A large-conductance mechanosensitive channel in E. coli encoded by mscL alone. Nature 368:265–268

    Article  CAS  PubMed  Google Scholar 

  45. Sukharev SI, Blount P, Martinac B, Kung C (1997) Mechanosensitive channels of Escherichia coli: the MscL gene, protein, and activities. Ann Rev Physiol 59:633–657

    Article  CAS  Google Scholar 

  46. Sukharev SI, Schroeder MJ, McCaslin DR (1999) Stoichiometry of the large conductance bacterial mechanosensitive channel of E. coli. A biochemical study. J Memb Biol 171:183–193

    Article  CAS  Google Scholar 

  47. Sukharev SI, Sigurdson WJ, Kung C, Sachs F (1999) Energetic and spatial parameters for gating of the bacterial large conductance mechanosensitive channel, MscL. J Gen Physiol 113:525–540

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  48. van den Bogaart G, Krasnikov V, Poolman B (2007) Dual-color fluorescence-burst analysis to probe protein efflux through the mechanosensitive channel MscL. Biophys J 92:1233–1240

    Article  PubMed Central  PubMed  Google Scholar 

  49. Walton TA, Rees DC (2013) Structure and stability of the C-terminal helical bundle of the E. coli mechanosensitive channel of large conductance. Protein Sci 22:1592–1601

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  50. Wang LC, Morgan LK, Godakumbura P, Kenney LJ, Anand GS (2012) The inner membrane histidine kinase EnvZ senses osmolality via helix-coil transitions in the cytoplasm. EMBO J 31:2648–2659

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  51. Wang Y, Liu Y, Deberg HA, Nomura T, Hoffman MT, Rohde PR, Schulten K, Martinac B, Selvin PR (2014) Single molecule FRET reveals pore size and opening mechanism of a mechano-sensitive ion channel. eLife 3:e01834

    PubMed Central  PubMed  Google Scholar 

  52. Yang LM, Wray R, Parker J, Wilson D, Duran RS, Blount P (2012) Three routes to modulate the pore size of the MscL channel/nanovalve. ACS Nano 6:1134–1141

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  53. Yoshimura K, Usukura J, Sokabe M (2008) Gating-associated conformational changes in the mechanosensitive channel MscL. Proc Natl Acad Sci U S A 105:4033–4038, d

    Article  CAS  PubMed Central  PubMed  Google Scholar 

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Acknowledgments

We thank Chris Gandhi, Rob Phillips, Elizabeth Haswell, and Ian Booth for stimulating discussions. N. Herrera is the recipient of a Gilliam graduate fellowship of the Howard Hughes Medical Institute, and C. Idigo received support from the US National Institutes of Health/National Research Service Award T32 GM07616. Research in the authors' lab was supported by US National Institutes of Health grant GM84211.

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Authors and Affiliations

  1. Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, 91125, USA

    Troy A. Walton, Chinenye A. Idigo, Nadia Herrera & Douglas C. Rees

  2. Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA, 91125, USA

    Douglas C. Rees

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  1. Troy A. Walton
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Correspondence to Douglas C. Rees.

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Walton, T.A., Idigo, C.A., Herrera, N. et al. MscL: channeling membrane tension. Pflugers Arch - Eur J Physiol 467, 15–25 (2015). https://doi.org/10.1007/s00424-014-1535-x

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