A new study led by the Scripps Research Institute has investigated how the Venus flytrap (Dionaea muscipula) – a species of carnivorous plant native to subtropical wetlands on the East Coast of the United States – snaps shut at the approach of prey.
According to the researchers, a protein mechanosensitive channel aptly named Flycatcher1 is the biological structure that enables these plants to catch their prey. Understanding the structure and functions of Flycatcher1 sheds more light on similar proteins in other organisms including plants, bacteria, or even humans.
“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,” said study co-senior author Andrew Ward, a professor of Integrative Structural Biology at the Scripps Institute.
Cells’ ability to sense pressure and movement is highly important for people’s sense of touch and hearing, as well as for many internal processes, such as the ability of the bladder to feel when it is full or the capacity of lungs to sense how much air is being breathed.
“Every new mechanosensitive channel that we study helps us make progress in understanding how these proteins can sense force and translate that to action and ultimately reveal more about human biology and health,” added co-senior author Ardem Patapoutian, a professor of Molecular and Cellular Neuroscience at Scripps who won the Nobel Prize in Physiology and Medicine for his research on the mechanosensitive channels allowing the human body to sense temperature and touch.
By using cryo-electron microscopy – a new technique which reveals the location of atoms within a frozen protein sample – the scientists analyzed the precise arrangement of molecules which form the Flycatcher1 protein channel in Venus flytrap plants and discovered that it is similar to a family of mechanosensitive channels found in bacteria (MscS).
However, while both Flycatcher1 and MscS channels exhibited seven groups of identical helices surrounding a central channel, Flycatcher1 had an unusual linker region extending outward from each group of helices. Like a switch, each linker could be flipped up or down, and appeared to be fundamental for the plant’s ability to close upon removal of pressure.
Further research is needed to determine whether Flycatcher1 is solely responsible for the snapping shut of Venus flytrap leaves, or whether other channels play complementary role. Moreover, the ways in which these protein channels relate to the mechanosensitive ion channels found in humans needs to be further investigated.
The study is published in the journal Nature Communications.