Amazing stuff!
"... Despite how different Venus flytraps are from humans, studying the structure and function of these mechanosensitive channels gives us a broader framework for understanding the ways that cells and organisms respond to touch and pressure ...
Mechanosensitive ion channels are like tunnels that span the membranes of cells. When jostled by movement, the channels open, letting charged molecules rush across. In response, cells then alter their behavior—a neuron might signal its neighbor, for instance. The ability for cells to sense pressure and movement is important for people’s senses of touch and hearing, but also for many internal body processes—from the ability of the bladder to sense that it’s full to the ability of lungs to sense how much air is being breathed. ...
Flycatcher1, caught researchers’ attention because its genetic sequence looked similar to a family of mechanosensitive channels, MscS, found in bacteria ...
In the new study, the researchers used cryo-electron microscopy—a cutting-edge technique that reveals the locations of atoms within a frozen protein sample—to analyze the precise arrangement of molecules that form the Flycatcher1 protein channel in Venus flytrap plants. They found that Flycatcher1 is, in many ways, similar to bacterial MscS proteins—seven groups of identical helices surrounding a central channel. But, unlike other MscS channels, Flycatcher1 has an unusual linker region extending outward from each group of helices. Like a switch, each linker can be flipped up or down. When the team determined the structure of Flycatcher1, they found six linkers in the down position, and just one flipped up. ..."
Mechanosensitive ion channels are like tunnels that span the membranes of cells. When jostled by movement, the channels open, letting charged molecules rush across. In response, cells then alter their behavior—a neuron might signal its neighbor, for instance. The ability for cells to sense pressure and movement is important for people’s senses of touch and hearing, but also for many internal body processes—from the ability of the bladder to sense that it’s full to the ability of lungs to sense how much air is being breathed. ...
Flycatcher1, caught researchers’ attention because its genetic sequence looked similar to a family of mechanosensitive channels, MscS, found in bacteria ...
In the new study, the researchers used cryo-electron microscopy—a cutting-edge technique that reveals the locations of atoms within a frozen protein sample—to analyze the precise arrangement of molecules that form the Flycatcher1 protein channel in Venus flytrap plants. They found that Flycatcher1 is, in many ways, similar to bacterial MscS proteins—seven groups of identical helices surrounding a central channel. But, unlike other MscS channels, Flycatcher1 has an unusual linker region extending outward from each group of helices. Like a switch, each linker can be flipped up or down. When the team determined the structure of Flycatcher1, they found six linkers in the down position, and just one flipped up. ..."
From the abstract:
"Flycatcher1 (FLYC1), a MscS homolog, has recently been identified as a candidate mechanosensitive (MS) ion channel involved in Venus flytrap prey recognition. FLYC1 is a larger protein and its sequence diverges from previously studied MscS homologs, suggesting it has unique structural features that contribute to its function. Here, we characterize FLYC1 by cryo-electron microscopy, molecular dynamics simulations, and electrophysiology. Akin to bacterial MscS and plant MSL1 channels, we find that FLYC1 central core includes side portals in the cytoplasmic cage that regulate ion preference and conduction, by identifying critical residues that modulate channel conductance. Topologically unique cytoplasmic flanking regions can adopt ‘up’ or ‘down’ conformations, making the channel asymmetric. ..."
Structural insights into the Venus flytrap mechanosensitive ion channel Flycatcher1 (open access)
The flycatcher
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