TY - JOUR
T1 - Sensing and responding to membrane tension
T2 - The bacterial MscL channel as a model system
AU - Iscla, Irene
AU - Blount, Paul
N1 - Funding Information:
P.B. was supported by grants I-1420 from the Welch Foundation, NNH08ZTT003N NRA from NASA, RP100146 from the Cancer Prevention and Research Institute of Texas, and AI080807 and GM061028 from the National Institutes of Health. I.I. was supported by grant 12SDG8740012 from the National American Heart Association.
PY - 2012/7/18
Y1 - 2012/7/18
N2 - Mechanosensors are important for many life functions, including the senses of touch, balance, and proprioception; cardiovascular regulation; kidney function; and osmoregulation. Many channels from an assortment of families are now candidates for eukaryotic mechanosensors and proprioception, as well as cardiovascular regulation, kidney function, and osmoregulation. Bacteria also possess two families of mechanosensitive channels, termed MscL and MscS, that function as osmotic emergency release valves. Of the two channels, MscL is the most conserved, most streamlined in structure, and largest in conductance at 3.6 nS with a pore diameter in excess of 30 Å; hence, the structural changes required for gating are exaggerated and perhaps more easily defined. Because of these properties, as well as its tractable nature, MscL represents a excellent model for studying how a channel can sense and respond to biophysical changes of a lipid bilayer. Many of the properties of the MscL channel, such as the sensitivity to amphipaths, a helix that runs along the membrane surface and is connected to the pore via a glycine, a twisting and turning of the transmembrane domains upon gating, and the dynamic changes in membrane interactions, may be common to other candidate mechanosensors. Here we review many of these properties and discuss their structural and functional implications.
AB - Mechanosensors are important for many life functions, including the senses of touch, balance, and proprioception; cardiovascular regulation; kidney function; and osmoregulation. Many channels from an assortment of families are now candidates for eukaryotic mechanosensors and proprioception, as well as cardiovascular regulation, kidney function, and osmoregulation. Bacteria also possess two families of mechanosensitive channels, termed MscL and MscS, that function as osmotic emergency release valves. Of the two channels, MscL is the most conserved, most streamlined in structure, and largest in conductance at 3.6 nS with a pore diameter in excess of 30 Å; hence, the structural changes required for gating are exaggerated and perhaps more easily defined. Because of these properties, as well as its tractable nature, MscL represents a excellent model for studying how a channel can sense and respond to biophysical changes of a lipid bilayer. Many of the properties of the MscL channel, such as the sensitivity to amphipaths, a helix that runs along the membrane surface and is connected to the pore via a glycine, a twisting and turning of the transmembrane domains upon gating, and the dynamic changes in membrane interactions, may be common to other candidate mechanosensors. Here we review many of these properties and discuss their structural and functional implications.
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U2 - 10.1016/j.bpj.2012.06.021
DO - 10.1016/j.bpj.2012.06.021
M3 - Review article
C2 - 22853893
AN - SCOPUS:84864755327
SN - 0006-3495
VL - 103
SP - 169
EP - 174
JO - Biophysical journal
JF - Biophysical journal
IS - 2
ER -