Epithelial Na+ channels and stomatin are expressed in rat trigeminal mechanosensory neurons.
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.
Fricke
B
B
Department of Neuroanatomy, Institute of Anatomy MA6/152, Ruhr University, Bochum, Germany. Britta.Fricke@ruhr-uni-bochum.de
Lints
R
R
Stewart
G
G
Drummond
H
H
Dodt
G
G
Driscoll
M
M
von Düring
M
M
D000818:Animals; D000906:Antibodies; D001798:Blood Proteins / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D004847:Epithelial Cells / Q000737:chemistry; D053503:Epithelial Sodium Channels; D015870:Gene Expression / Q000502:physiology; D007150:Immunohistochemistry; D008465:Mechanoreceptors / Q000737:chemistry; D009413:Nerve Fibers, Myelinated / Q000737:chemistry; D009475:Neurons, Afferent / Q000737:chemistry* / Q000648:ultrastructure; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D015398:Signal Transduction / Q000502:physiology; D015222:Sodium Channels / Q000032:analysis* / Q000235:genetics / Q000276:immunology; D014276:Trigeminal Nerve / Q000166:cytology*; D014738:Vibrissae / Q000294:innervation
D000906:Antibodies; D001798:Blood Proteins; D053503:Epithelial Sodium Channels; D012333:RNA, Messenger; D015222:Sodium Channels