Fricke B, Lints R, Stewart G, Drummond H, Dodt G, Driscoll M, von Düring M
Department of Neuroanatomy, Institute of Anatomy MA6/152, Ruhr University, Bochum, Germany.
Cell Tissue Res. 2000 Mar;299(3):327-34. doi: 10.1007/s004419900153.
Caenorhabditis elegans MEC-4 and MEC-10 are subunits of the degenerin/epithelial Na+ channel (DEG/ENaC) ion channel superfamily thought to be associated with MEC-2 (a stomatin-like protein) in a mechanotransducing molecular complex in specialized touch sensory neurons. A key question is whether analogous molecular complexes in higher organisms transduce mechanical signals. To address this question, we selected mechanoreceptors of the rat vibrissal follicle-sinus complex in the mystacial pad and the trigeminal ganglia for an immunocytochemical and molecular biological study. RT-PCR of poly(A+) mRNA of rat trigeminal ganglia indicated that alpha-, beta-, and gamma-ENaC and stomatin mRNA are expressed in rat trigeminal ganglia. Using immunocytochemistry, we found that alpha-, beta-, and gamma-ENaC subunits and stomatin are localized in the perikarya of the trigeminal neurons and in a minor fraction of their termination site in the vibrissal follicle-sinus complex, where longitudinal lanceolate endings are immunopositive. We conclude that alpha-, beta-, and gamma-ENaC subunits as well as the candidate interacting protein stomatin are coexpressed in a mammalian mechanoreceptor, a location consistent with a possible role in mechanotransduction.
秀丽隐杆线虫的MEC - 4和MEC - 10是退化素/上皮钠离子通道（DEG/ENaC）离子通道超家族的亚基，在特殊的触觉感觉神经元的机械转导分子复合物中，它们被认为与MEC - 2（一种类stomatin蛋白）相关。一个关键问题是高等生物中类似的分子复合物是否能转导机械信号。为了解决这个问题，我们选择了大鼠触须垫中的触须毛囊 - 窦复合体和三叉神经节的机械感受器进行免疫细胞化学和分子生物学研究。大鼠三叉神经节的多聚腺苷酸（poly(A+)）mRNA的逆转录聚合酶链反应（RT-PCR）表明，α-、β-和γ-ENaC以及stomatin mRNA在大鼠三叉神经节中表达。通过免疫细胞化学，我们发现α-、β-和γ-ENaC亚基以及stomatin定位于三叉神经元的胞体以及它们在触须毛囊 - 窦复合体中一小部分的终末部位，在那里纵向的柳叶状终末呈免疫阳性。我们得出结论，α-、β-和γ-ENaC亚基以及候选相互作用蛋白stomatin在哺乳动物的机械感受器中共表达，这一位置与它们在机械转导中可能发挥的作用一致。
