Petrov, Evgeny and Palanivelu, Dinesh and Constantine, Maryrose and Rohde, Paul R and Cox, Charles D and Nomura, Takeshi and Minor, Daniel L and Martinac, Boris (2013) Patch-clamp characterization of the MscS-like mechanosensitive channel from Silicibacter pomeroyi. Biophysical Journal, 104 (7). pp.1426-34. ISSN 1542-0086 (PMC OA)
Full text not available from this repository.Abstract
Based on sequence similarity, the sp7 gene product, MscSP, of the sulfur-compound-decomposing Gram-negative marine bacterium Silicibacter pomeroyi belongs to the family of MscS-type mechanosensitive channels. To investigate MscSP channel properties, we measured its response to membrane tension using the patch-clamp technique on either a heterologous expression system using giant spheroplasts of MJF465 Escherichia coli strain (devoid of mechanosensitive channels MscL, MscS, and MscK), or on purified MscSP protein reconstituted in azolectin liposomes. These experiments showed typical pressure-dependent gating properties of a stretch-activated channel with a current/voltage plot indicating a rectifying behavior and weak preference for anions similar to the MscS channel of E. coli. However, the MscSP channel exhibited functional differences with respect to conductance and desensitization behavior, with the most striking difference between the two channels being the lack of inactivation in MscSP compared with MscS. This seems to result from the fact that although MscSP has a Gly in an equivalent position to MscS (G113), a position that is critical for inactivation, MscSP has a Glu residue instead of an Asn in a position that was recently shown to allosterically influence MscS inactivation, N117. To our knowledge, this study describes the first electrophysiological characterization of an MscS-like channel from a marine bacterium belonging to sulfur-degrading α-proteobacteria.
(ARC DP0769983; NHMRC 635525; the National Institutes of Health NIH U54GM094625).
| Item Type: | Article |
|---|---|
| Subjects: | R Medicine > R Medicine (General) |
| Depositing User: | Repository Administrator |
| Date Deposited: | 22 Dec 2015 03:53 |
| Last Modified: | 22 Mar 2016 04:13 |
| URI: | https://eprints.victorchang.edu.au/id/eprint/62 |
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