Functional analysis in a model sea anemone reveals phylogenetic complexity and a role in cnidocyte discharge of DEG/ENaC ion channels

bioRxiv (Cold Spring Harbor Laboratory)

Abstract

Abstract Ion channels of the DEG/ENaC family share a similar structure but serve strikingly diverse biological functions, such as Na + reabsorption, mechanosensing, proton-sensing, chemosensing and cell-cell communication via neuropeptides. This functional diversity raises the question of the ancient function of DEG/ENaCs. Using an extensive phylogenetic analysis across many different animal groups, we found a surprising diversity of DEG/ENaCs already in Cnidaria (corals, sea anemones, hyrdoids and jellyfish). Using a combination of gene expression analysis, electrophysiological and functional studies combined with pharmacological inhibition as well as genetic knockout in the model cnidarian Nematostella vectensis , we reveal an unanticipated role for a proton-sensitive DEG/ENaC in discharge of N. vectensis cnidocytes, the stinging cells typifying all cnidarians. Our study supports the view that DEG/ENaCs are versatile channels that have been co-opted for diverse functions since their early occurrence in animals and that respond to simple and ancient stimuli, such as omnipresent protons. Teaser The analysis of an ion channel class in a sea anemone reveals its role in acidity-induced discharge of stinging cells.

Authors 5

1. José María Aguilar-Camacho

   Hebrew University of Jerusalem

   Affiliation as printed

   Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel

2. Katharina Foreman Aachen Institute of Physiology

   RWTH Aachen University

   Affiliation as printed

   Institute of Physiology, RWTH Aachen University, Aachen, Germany

3. Reuven Aharoni

   Hebrew University of Jerusalem

   Affiliation as printed

   Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel

4. Stefan Gründer corresponding Aachen Institute of Physiology

   RWTH Aachen University

   Affiliation as printed

   Institute of Physiology, RWTH Aachen University, Aachen, Germany

5. Yehu Moran corresponding

   Hebrew University of Jerusalem

   Affiliation as printed

   Department of Ecology, Evolution and Behavior, Alexander Silberman Institute of Life Sciences, Faculty of Science, The Hebrew University of Jerusalem, Jerusalem, Israel