Stomatin and sensory neuron mechanotransduction.
Somatic sensory neurons of the dorsal root ganglia are necessary for a large part of our mechanosensory experience. However, we only have a good knowledge of the molecules required for mechanotransduction in simple invertebrates such as the nematode Caenorhabiditis elegans. In C. elegans, a number of so-called mec genes have been isolated that are required for the transduction of body touch. One such gene, mec-2 codes for an integral membrane protein of the stomatin family, a large group of genes with a stomatin homology domain. Using stomatin null mutant mice, we have tested the hypothesis that the founding member of this family, stomatin might play a role in the transduction of mechanical stimuli by primary sensory neurons. We used the in vitro mouse skin nerve preparation to record from a large population of low- and high-threshold mechanoreceptors with myelinated A-fiber (n = 553) and unmyelinated C-fiber (n = 157) axons. One subtype of mechanoreceptor, the d-hair receptor, which is a rapidly adapting mechanoreceptor, had reduced sensitivity to mechanical stimulation in the absence of stomatin. Other cutaneous mechanoreceptors, including nociceptive C-fibers were not affected by the absence of a functional stomatin protein. Patch-clamp analysis of presumptive D-hair receptor mechanoreceptive neurons, which were identified by a characteristic rosette morphology in culture, showed no change in membrane excitability in the absence of the stomatin protein. We conclude that stomatin is required for normal mechanotransduction in a subpopulation of vertebrate sensory neurons.
Martinez-Salgado
Carlos
C
Department of Neuroscience, Max-Delbrück Center for Molecular Medicine and Charité Universitätsmedizin Berlin, Robert-Rössle Str, Berlin-Buch, Germany.
Benckendorff
Anne G
AG
Chiang
Li-Yang
LY
Wang
Rui
R
Milenkovic
Nevena
N
Wetzel
Christiane
C
Hu
Jing
J
Stucky
Cheryl L
CL
Parra
Marilyn G
MG
Mohandas
Narla
N
Lewin
Gary R
GR
D000818:Animals; D001798:Blood Proteins / Q000235:genetics* / Q000502:physiology*; D004594:Electrophysiology; D006197:Hair / Q000502:physiology; D008465:Mechanoreceptors / Q000502:physiology; D040542:Mechanotransduction, Cellular / Q000502:physiology*; D008565:Membrane Proteins / Q000235:genetics* / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009413:Nerve Fibers, Myelinated / Q000502:physiology; D036421:Nerve Fibers, Unmyelinated / Q000502:physiology; D009475:Neurons, Afferent / Q000502:physiology*; D009619:Nociceptors / Q000502:physiology; D018408:Patch-Clamp Techniques; D012867:Skin / Q000294:innervation*
D001798:Blood Proteins; C488964:Stom protein, mouse; D008565:Membrane Proteins