Mechanosensitive channel function

A third mechanosensitive channel of mini conductance (MscM) has been functionally identified in E. coli (Berrier et al., 1989, 1996), although the encoding gene has not yet been reported. This channel has a conductance of less than half that of MscS (0.1—0.4 nS), with slow opening/closing kinetics relative to MscS, and especially MscL (Berrier et al., 1993). In contrast to MscL and MscS, MscM has pronounced cation selectivity. 

Martinac B. 3.5 Billion years of mechanosensory transduction structure and function of mechanosensitive channels in prokaryotes. Current Topics in Membranes, vol. 58. Owen P. Hamill, ed. 2007. Elsevier Inc., San Diego CA., pp. 25—57. 

Maurer JA, Ehnore DE, Lester HA, Dougherty DA. Comparing and contrasting Escherichia coli and Mycobacterium tuberculosis mechanosensitive channels (MscL)—new gain of function mutations in the loop region. J. Biol. Chem. 2000 275 22238-22244. 

Hashimoto K, Nakamura K, Kuroda T, Yabe I, Nakamatsu T, Kawasaki H. (2010). The protein encoded by NCgll221 in Corynebacterium glutamicum functions as a mechanosensitive channel. Biosci Biotechnol Biochem, 74, 2546-2549. 

The pore-forming a 1 subunits Cay3.1-Cav3.3 are responsible for T-type Ca + currents and are considered LVA since they are activate at membrane potentials far more hyperpolarized than their HVA counterparts (Catterall et al. 2005). Intrigu-ingly, T-type Ca + channels are crucial for the normal function of mouse D-hair mechanosensitive fibers (Shin et al. 2003) that adapt rapidly to mechanical stimuli in a manner qualitatively similar to airway nodose A5 cough receptoT fibers (McAlexander et al. 1999). 

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