Identification of a novel protein complex containing ASIC1a and GABAA receptors and their interregulation

PLoS One. 2014 Jun 12;9(6):e99735. doi: 10.1371/journal.pone.0099735. eCollection 2014.

Abstract

Acid-sensing ion channels (ASICs) belong to the family of the epithelial sodium channel/degenerin (ENaC/DEG) and are activated by extracellular protons. They are widely distributed within both the central and peripheral nervous systems. ASICs were modified by the activation of γ-aminobutyric acid receptors (GABAA), a ligand-gated chloride channels, in hippocampal neurons. In contrast, the activity of GABAA receptors were also modulated by extracellular pH. However so far, the mechanisms underlying this intermodulation remain obscure. We hypothesized that these two receptors-GABAA receptors and ASICs channels might form a novel protein complex and functionally interact with each other. In the study reported here, we found that ASICs were modified by the activation of GABAA receptors either in HEK293 cells following transient co-transfection of GABAA and ASIC1a or in primary cultured dorsal root ganglia (DRG) neurons. Conversely, activation of ASIC1a also modifies the GABAA receptor-channel kinetics. Immunoassays showed that both GABAA and ASIC1a proteins were co-immunoprecipitated mutually either in HEK293 cells co-transfected with GABAA and ASIC1a or in primary cultured DRG neurons. Our results indicate that putative GABAA and ASIC1a channels functionally interact with each other, possibly via an inter-molecular association by forming a novel protein complex.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acid Sensing Ion Channels / genetics*
  • Acid Sensing Ion Channels / metabolism*
  • Animals
  • Cells, Cultured
  • Cloning, Molecular
  • Ganglia, Spinal / metabolism
  • Gene Expression Regulation
  • HEK293 Cells
  • Humans
  • Neurons / metabolism
  • Protein Binding / genetics
  • Rats
  • Rats, Wistar
  • Receptors, GABA-A / genetics*
  • Receptors, GABA-A / metabolism*
  • Transfection

Substances

  • ASIC1 protein, human
  • Acid Sensing Ion Channels
  • GABRA1 protein, human
  • GABRB2 protein, human
  • Receptors, GABA-A

Grants and funding

This work was supported by grants from the Promotive Research Fund for Excellent Young and Middle-Aged Scientists of Shandong Province (No. BS2010SW029) and the National Natural Science Foundation of China (No. 31171108). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.