D
IPR006685

Mechanosensitive ion channel MscS

InterPro entry
Short nameMscS_channel_2nd
Overlapping
homologous
superfamilies
 

Description

This entry includes small conductance mechanosensitive channels (MscS), which assembles to a homoheptameric complex
[6, 7, 11, 3, 9, 8]
. Each monomer consists of a N-terminal transmembrane region and a large cytoplasmic segment composed of a five-stranded antiparallel β-sheet (middle/second) domain and a C-terminal α/β-domain
[3, 9, 8, 10]
.

This entry represents the all-β domain which adopts a SH3-like barrel structure.

Mechanosensitive (MS) channels provide protection against hypo-osmotic shock, responding both to stretching of the cell membrane and to membrane depolarisation. They are present in the membranes of organisms from the three domains of life: bacteria, archaea, and eukarya
[1]
. There are two families of MS channels: large-conductance MS channels (MscL) and small-conductance MS channels (MscS or YGGB). The pressure threshold for MscS opening is 50% that of MscL
[2]
. The MscS family is much larger and more variable in size and sequence than the MscL family. Much of the diversity in MscS proteins occurs in the size of the transmembrane regions, which ranges from three to eleven transmembrane helices, although the three C-terminal helices are conserved.

MscS folds as a homo-heptamer with a cylindrical shape, and can be divided into transmembrane and extramembrane regions: an N-terminal periplasmic region, a transmembrane region, and a C-terminal cytoplasmic region (middle and C-terminal domains). The transmembrane region forms a channel through the membrane that opens into a chamber enclosed by the extramembrane portion, the latter connecting to the cytoplasm through distinct portals
[2, 3]
.

In the fission yeast Schizosaccharomyces pombe the mechanosensitive ion channel proteins are known as msy1 and msy2
[5, 4]
.

References

1.Two families of mechanosensitive channel proteins. Pivetti CD, Yen MR, Miller S, Busch W, Tseng YH, Booth IR, Saier MH Jr. Microbiol. Mol. Biol. Rev. 67, 66-85, table of contents, (2003). View articlePMID: 12626684

2.Crystal structure of Escherichia coli MscS, a voltage-modulated and mechanosensitive channel. Bass RB, Strop P, Barclay M, Rees DC. Science 298, 1582-7, (2002). View articlePMID: 12446901

3.Mechanosensitive channel gating by delipidation. Flegler VJ, Rasmussen A, Borbil K, Boten L, Chen HA, Deinlein H, Halang J, Hellmanzik K, Loffler J, Schmidt V, Makbul C, Kraft C, Hedrich R, Rasmussen T, Bottcher B. Proc Natl Acad Sci U S A 118, e2107095118, (2021). PMID: 34376558

4.Mechanosensitive channels Msy1 and Msy2 are required for maintaining organelle integrity upon hypoosmotic shock in Schizosaccharomyces pombe. Nakayama Y, Hirata A, Iida H. FEMS Yeast Res 14, 992-4, (2014). PMID: 25041276

5.Organellar mechanosensitive channels in fission yeast regulate the hypo-osmotic shock response. Nakayama Y, Yoshimura K, Iida H. Nat Commun 3, 1020, (2012). View articlePMID: 22910366

6.Structural and functional differences between two homologous mechanosensitive channels of Methanococcus jannaschii. Kloda A, Martinac B. EMBO J. 20, 1888-96, (2001). View articlePMID: 11296222

7.Molecular identification of a mechanosensitive channel in archaea. Kloda A, Martinac B. Biophys. J. 80, 229-40, (2001). View articlePMID: 11159397

8.Open and shut: crystal structures of the dodecylmaltoside solubilized mechanosensitive channel of small conductance from Escherichia coli and Helicobacter pylori at 4.4 A and 4.1 A resolutions. Lai JY, Poon YS, Kaiser JT, Rees DC. Protein Sci 22, 502-9, (2013). PMID: 23339071

9.Conformational state of the MscS mechanosensitive channel in solution revealed by pulsed electron-electron double resonance (PELDOR) spectroscopy. Pliotas C, Ward R, Branigan E, Rasmussen A, Hagelueken G, Huang H, Black SS, Booth IR, Schiemann O, Naismith JH. Proc. Natl. Acad. Sci. U.S.A. 109, E2675-82, (2012). View articlePMID: 23012406

10.Structure and molecular mechanism of an anion-selective mechanosensitive channel of small conductance. Zhang X, Wang J, Feng Y, Ge J, Li W, Sun W, Iscla I, Yu J, Blount P, Li Y, Yang M. Proc. Natl. Acad. Sci. U.S.A. 109, 18180-5, (2012). View articlePMID: 23074248

11.Mechanosensitive channels in prokaryotes. Martinac B. Cell. Physiol. Biochem. 11, 61-76, (2001). View articlePMID: 11275684

GO terms

molecular function

  • None

cellular component

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