RRC ID 46016
Author Arnadóttir J, O'Hagan R, Chen Y, Goodman MB, Chalfie M.
Title The DEG/ENaC protein MEC-10 regulates the transduction channel complex in Caenorhabditis elegans touch receptor neurons.
Journal J Neurosci
Abstract Gentle touch sensation in Caenorhabditis elegans is mediated by the MEC-4/MEC-10 channel complex, which is expressed exclusively in six touch receptor neurons (TRNs). The complex contains two pore-forming subunits, MEC-4 and MEC-10, as well as the accessory subunits MEC-2, MEC-6, and UNC-24. MEC-4 is essential for channel function, but beyond its role as a pore-forming subunit, the functional contribution of MEC-10 to the channel complex and to touch sensation is unclear. We addressed this question using behavioral assays, in vivo electrophysiological recordings from TRNs, and heterologous expression of mutant MEC-10 isoforms. Animals with a deletion in mec-10 showed only a partial loss of touch sensitivity and a modest decrease in the size of the mechanoreceptor current (MRC). In contrast, five previously identified mec-10 alleles acted as recessive gain-of-function alleles that resulted in complete touch insensitivity. Each of these alleles produced a substantial decrease in MRC size and a shift in the reversal potential in vivo. The latter finding indicates that these mec-10 mutations alter the ionic selectivity of the transduction channel in vivo. All mec-10 mutant animals had properly localized channel complexes, indicating that the loss of MRCs was not attributable to a dramatic mislocalization of transduction channels. Finally, electrophysiological examination of heterologously expressed complexes suggests that mutant MEC-10 proteins may affect channel current via MEC-2.
Volume 31(35)
Pages 12695-704
Published 2011-8-31
DOI 10.1523/JNEUROSCI.4580-10.2011
PII 31/35/12695
PMID 21880930
PMC PMC3172708
MeSH Animals Animals, Genetically Modified Caenorhabditis elegans Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism* Gene Expression Regulation / genetics Immunoprecipitation / methods In Vitro Techniques Mechanotransduction, Cellular / genetics Mechanotransduction, Cellular / physiology* Membrane Potentials / genetics Membrane Potentials / physiology Membrane Proteins / deficiency Membrane Proteins / genetics Membrane Proteins / metabolism* Microinjections / methods Mutation, Missense / genetics Oocytes Physical Stimulation / methods Point Mutation / genetics RNA Interference / physiology Sensory Receptor Cells / metabolism* Sodium Channels / genetics Sodium Channels / metabolism Touch / genetics*
IF 5.674
Times Cited 42
C.elegans tm1552