Defying a carnivorous nature: how Venus flytraps snap shut – Digital Journal

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By Beatriz Moisset – Own work, CC BY-SA 4.0.

Scientists have determined how Venus flytrap plants (Dionaea muscipula) carry out their characteristic clicking mechanism, where they ‘slam shut’ when an insect or arachnid enters. The popping mechanism is a combination of an interaction between elasticity, turgor, and growth.

This is related to a mechanosensitive ion channel. What is interesting is that this mechanism is related to channels found in a variety of other organisms. Mechanosensitivity is a specific response to mechanical stimulation, and this response is common to a wide variety of different cell types.

The research comes from the Scripps Research Institute and has focused on a three-dimensional structure of a protein channel called ‘Flycatcher1’ in relation to the plant. This channel allows Venus flytrap plants to snap shut in response to prey. The Venus flytrap is found in nitrogen- and phosphorus-poor environments, such as swamps and damp savannahs (the insect’s prey provides the nitrogen needed for protein formation that soil cannot).

the structure of the curiously named Flycatcher1 answers a longstanding question about the remarkable tactile feedback sensitivity of Venus flytraps. The trigger point is the mechanosensitive ion channels. These are a bit like tunnels and go through the cell membranes.

When jostled by movement, the channels open, allowing charged molecules to pass through. In response, cells modify their behavior. To gain insight into this process, the researchers deployed cryoelectron microscopy. This is a new technique capable of revealing the location of atoms within a frozen protein sample.

This level of analysis showed that Flycatcher1 is similar to the bacterial MscS proteins and occurs as seven clusters of identical helices surrounding a central channel. However, Flycatcher1 has an atypical linker region extending out from each helix cluster. Similar to a switch, each linker can be flipped up or down.

By studying the mutations, it was established that the conformations of these seven linkers are relevant to the functioning of the channel.

The structure also provides researchers with an understanding of how similar proteins might operate in other organisms, including plants and bacteria, as well as proteins in the human body, which possess similar functions. This is related to understanding how cells and organisms respond to touch and pressure.

The cells’ ability to sense pressure and movement is part of people’s senses of touch and hearing. When this doesn’t work as intended, it can lead to complications with a number of internal processes in the body, such as the bladder’s ability to feel that it’s full, or the lungs’ ability to sense how much air is being inhaled.

The investigation it appears in the newspaper nature communicationstitled “Structural information on the mechanosensitive ion channel of the Venus flytrap Flycatcher1”.

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