title: Two novel DEG/ENaC channel subunits expressed in glia are needed for nose-touch sensitivity in Caenorhabditis elegans.
abstract: Neuronal DEG/ENaC (degenerin and epithelial Na(+) channel) Na(+) channels have been implicated in touch sensation. For example, MEC-4 is expressed in touch neurons in Caenorhabditis elegans and mediates gentle-touch response. Similarly, homologous mammalian ASIC2 and ASIC3 are expressed in sensory neurons and produce touch phenotypes when knocked out in mice. Here, we show that novel DEG/ENaC subunits DELM-1 and DELM-2 (degenerin-like channel mechanosensory linked-1 and degenerin-like channel mechanosensory linked-2) are expressed in glia associated with touch neurons in C. elegans and that their knock-out causes defects in mechanosensory behaviors related to nose touch and foraging, which are mediated by OLQ and IL1 sensory neurons. Cell-specific rescue supports that DELM-1 and DELM-2 are required cell-autonomously in glia to orchestrate mechanosensory behaviors. Electron microscopy reveals that in delm-1 knock-outs, OLQ and IL1 sensory neurons and associated glia are structurally normal. Furthermore, we show that knock-out of DELM-1 and DELM-2 does not disrupt the expression or cellular localization of TRPA-1, a TRP channel needed in OLQ and IL1 neurons for touch behaviors. Rather, rescue of the delm-1 nose-touch-insensitive phenotype by expression of a K(+) channel in socket glia and of a cationic channel in OLQ neurons suggests that DELM channels set basal neuronal excitability. Together, our data show that DELM-1 and DELM-2 are expressed in glia associated with touch neurons where they are not needed for neuronal structural integrity or cellular distribution of neuronal sensory channels, but rather for their function.
authors: Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, Florida 33136, USA.
authors: Lu
authors: L
authors: Han
authors: Ying
authors: Y
authors: Wang
authors: Rachele
authors: R
authors: Sangaletti
authors: Giulia
authors: G
authors: D'Urso
authors: Yun
authors: Y
authors: Lu
authors: Shai
authors: S
authors: Shaham
authors: Laura
authors: L
authors: Bianchi
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D062626:Degenerin Sodium Channels / Q000235:genetics / Q000378:metabolism*; D053503:Epithelial Sodium Channels / Q000235:genetics / Q000378:metabolism*; D040542:Mechanotransduction, Cellular / Q000502:physiology; D009457:Neuroglia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism; D014110:Touch / Q000502:physiology*; D055698:Touch Perception / Q000502:physiology*
chemical_list: D029742:Caenorhabditis elegans Proteins; D062626:Degenerin Sodium Channels; D053503:Epithelial Sodium Channels