title: Annexin II light chain p11 promotes functional expression of acid-sensing ion channel ASIC1a.
abstract: Acid-sensing ion channels (ASICs) have been implicated in a wide variety of physiological functions. We have used a rat dorsal root ganglion cDNA library in a yeast two-hybrid assay to identify sensory neuron proteins that interact with ASICs. We found that annexin II light chain p11 physically interacts with the N terminus of ASIC1a, but not other ASIC isoforms. Immunoprecipitation studies confirmed an interaction between p11 and ASIC1 in rat dorsal root ganglion neurons in vivo. Coexpression of p11 and ASIC1a in CHO-K1 cells led to a 2-fold increase in expression of the ion channel at the cell membrane as determined by membrane-associated immunoreactivity and cell-surface biotinylation. Consistent with these findings, peak ASIC1a currents in transfected CHO-K1 cells were up-regulated 2-fold in the presence of p11, whereas ASIC3-mediated currents were unaffected by p11 expression. Neither the pH dependence of activation nor the rates of desensitization were altered by p11, suggesting that its primary role in regulating ASIC1a activity is to enhance cell-surface expression of ASIC1a. These data demonstrate that p11, already known to traffic members of the voltage-gated sodium and potassium channel families as well as transient receptor potential and chloride channels, also plays a selective role in enhancing ASIC1a functional expression.
authors.affiliation: Molecular Nociception Group, Department of Biology, University College London, Gower Street, London WC1E 6BT, United Kingdom.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Donier
authors.forename: François
authors.initials: F
authors.lastname: Rugiero
authors.forename: Kenji
authors.initials: K
authors.lastname: Okuse
authors.forename: John N
authors.initials: JN
authors.lastname: Wood
mesh_terms: D062565:Acid Sensing Ion Channels; D000818:Animals; D017306:Annexin A2 / Q000378:metabolism / Q000502:physiology*; D019921:Biotinylation; D015153:Blotting, Western; D016466:CHO Cells; D002462:Cell Membrane / Q000378:metabolism / Q000502:physiology; D006224:Cricetinae; D018076:DNA, Complementary / Q000378:metabolism; D004594:Electrophysiology; D005727:Ganglia, Spinal / Q000378:metabolism; D005786:Gene Expression Regulation; D015723:Gene Library; D005982:Glutathione Transferase / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D007477:Ions; D008565:Membrane Proteins / Q000096:biosynthesis* / Q000502:physiology*; D051379:Mice; D018345:Mice, Knockout; D009419:Nerve Tissue Proteins / Q000096:biosynthesis* / Q000502:physiology*; D009474:Neurons / Q000378:metabolism; D018408:Patch-Clamp Techniques; D011485:Protein Binding; D020033:Protein Isoforms; D017434:Protein Structure, Tertiary; D051381:Rats; D009418:S100 Proteins / Q000378:metabolism / Q000502:physiology*; D015222:Sodium Channels / Q000096:biosynthesis* / Q000502:physiology*; D014162:Transfection; D020798:Two-Hybrid System Techniques; D000099248:S100 Calcium Binding Protein A10
chemical_list: D062565:Acid Sensing Ion Channels; D017306:Annexin A2; D018076:DNA, Complementary; D005982:Glutathione Transferase; D049452:Green Fluorescent Proteins; D007477:Ions; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D020033:Protein Isoforms; D009418:S100 Proteins; D015222:Sodium Channels; D000099248:S100 Calcium Binding Protein A10; C568267:ASIC1 protein, mouse; C568269:ASIC3 protein, rat; C568268:Asic1 protein, rat