這個蛋白讓人類感知指尖觸覺
作者:
小柯機器人發布時間:2020/12/8 13:50:02
德國馬克斯·德布呂克分子醫學中心Gary R. Lewin課題組發現,USH2A是一種梅氏小體蛋白,是小鼠和人類正常振動感應所必需的。該研究於2020年12月7日在線發表於《自然—神經科學》。
研究人員發現在梅氏小體內的Schwann末端細胞中發現了USH2A,這是一種具有極大胞外域的跨膜蛋白。致病性USH2A突變會導致Usher症候群,並伴有聽力損失和視力障礙。研究人員發現,具有雙等位基因致病性USH2A突變的患者,以及缺乏USH2A的突變小鼠,在觸覺感知上也有明確和特定的損傷。根據Ush2a-/-小鼠的記錄,前爪迅速適應了支配梅氏小體的機械感受器,並顯示其振動敏感性大大降低。但是,在感覺神經元中未發現USH2A蛋白。因此,梅氏小體末端器官中USH2A的缺失降低了機械感受器的敏感性以及振動知覺。因此,一種系鏈蛋白需要用於促進小幅度振動的檢測,這對於感知細粒觸覺表面必不可少。
研究人員介紹,指尖機械感受器包括感覺神經元末梢以及形成終末器官的特殊皮膚細胞。敏感的振動感應神經元與皮膚中的梅氏小體相關。
附:英文原文
Title: USH2A is a Meissner’s corpuscle protein necessary for normal vibration sensing in mice and humans
Author: Fred Schwaller, Valrie Bgay, Gema Garca-Garca, Francisco J. Taberner, Rabih Moshourab, Brennan McDonald, Trevor Docter, Johannes Khnemund, Julia Ojeda-Alonso, Ricardo Paricio-Montesinos, Stefan G. Lechner, James F. A. Poulet, Jose M. Millan, Gary R. Lewin
Issue&Volume: 2020-12-07
Abstract: Fingertip mechanoreceptors comprise sensory neuron endings together with specialized skin cells that form the end-organ. Exquisitely sensitive, vibration-sensing neurons are associated with Meissner’s corpuscles in the skin. In the present study, we found that USH2A, a transmembrane protein with a very large extracellular domain, was found in terminal Schwann cells within Meissner’s corpuscles. Pathogenic USH2A mutations cause Usher’s syndrome, associated with hearing loss and visual impairment. We show that patients with biallelic pathogenic USH2A mutations also have clear and specific impairments in vibrotactile touch perception, as do mutant mice lacking USH2A. Forepaw rapidly adapting mechanoreceptors innervating Meissner’s corpuscles, recorded from Ush2a/ mice, showed large reductions in vibration sensitivity. However, the USH2A protein was not found in sensory neurons. Thus, loss of USH2A in corpuscular end-organs reduced mechanoreceptor sensitivity as well as vibration perception. Thus, a tether-like protein is required to facilitate detection of small-amplitude vibrations essential for the perception of fine-grained tactile surfaces.
DOI: 10.1038/s41593-020-00751-y
Source: https://www.nature.com/articles/s41593-020-00751-y