Xin Liang’s Group from School of Life Sciences in Tsinghua University revealed novel mechanisms of Fly Mechanotransduction
The conversion of mechanical signals into electrical signals in cells, known as mechanotransduction, is required for the perception of sound, touch, and acceleration. Mechanotransduction occurs much more rapidly than visual phototransduction or olfactory transduction. This suggests that in mechanotransduction, mechanical stimuli are directly converted to intracellular signals rather than through a second messenger as in visual and olfactory transduction. Based on electrophysiological and mechanical measurements, it has been hypothesized that the mechanotransduction apparatus contains a transduction channel coupled to a molecular spring. A key question towards understanding mechanotransduction is how the forces are conveyed to the force-sensitive channel.
Researchers in the group of Xin Liang at School of Life Sciences in Tsinghua University sought to address this question. With the support from colleagues in School of Aerospace Engineering, they studied ultrastructural-mechanics of fly mechanoreceptors using electron microscopic tomography, fly genetics, live-cell imaging and mechanical modeling. They discovered that the mechanoreceptive organelle in fly campaniform mechanoreceptors contains thousands of force-sensitive ion channels that are arranged in a regular pattern, aligned to the intracellular microtubule cytoskeleton. Using mechanical modeling, they found that the pattern is structurally and functionally optimized, because more force-sensitive channels are located at regions that are subject to larger activating forces. Based on these findings, the researchers propose that such a pattern enhances the sensitivity and broadens the dynamic range of mechanosensation in this type of mechanoreceptor. This study revealed a novel working mechanism of fly mechanotransduction and opened the gate to further explore the molecular basis of fly mechanosensation.
This work is supported by funding from Nation Key R&D Program of China, National Natural Sciences Foundation of China, Qingdao National Laboratory for Marine Science and Technology and Tsinghua-Peking Joint Center for Life Sciences. Xin Liang is also a Max-Planck Partner Group leader.
Original Publication:
(From School of Life Sciences)
