title: AMIGO is an auxiliary subunit of the Kv2.1 potassium channel.
abstract: Kv2.1 is a potassium channel α-subunit abundantly expressed throughout the brain. It is a main component of delayed rectifier current (I(K)) in several neuronal types and a regulator of excitability during high-frequency firing. Here we identify AMIGO (amphoterin-induced gene and ORF), a neuronal adhesion protein with leucine-rich repeat and immunoglobin domains, as an integral part of the Kv2.1 channel complex. AMIGO shows extensive spatial and temporal colocalization and association with Kv2.1 in the mouse brain. The colocalization of AMIGO and Kv2.1 is retained even during stimulus-induced changes in Kv2.1 localization. AMIGO increases Kv2.1 conductance in a voltage-dependent manner in HEK cells. Accordingly, inhibition of endogenous AMIGO suppresses neuronal I(K) at negative membrane voltages. In conclusion, our data indicate AMIGO as a function-modulating auxiliary subunit for Kv2.1 and thus provide new insights into regulation of neuronal excitability.
authors: Neuroscience Center, University of Helsinki, PO Box 56, Helsinki FI-00014, Finland. marjaana.kiiltomaki@helsinki.fi
authors: Marjaana A
authors: MA
authors: Peltola
authors: Juha
authors: J
authors: Kuja-Panula
authors: Sari E
authors: SE
authors: Lauri
authors: Tomi
authors: T
authors: Taira
authors: Heikki
authors: H
authors: Rauvala
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002478:Cells, Cultured; D057809:HEK293 Cells; D006624:Hippocampus / Q000166:cytology / Q000378:metabolism; D006801:Humans; D015640:Ion Channel Gating; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D009474:Neurons / Q000166:cytology / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D021122:Protein Subunits / Q000378:metabolism*; D021381:Protein Transport; D051381:Rats; D051669:Shab Potassium Channels / Q000378:metabolism*
chemical_list: C570804:AMIGO protein, mouse; D008565:Membrane Proteins; D021122:Protein Subunits; D051669:Shab Potassium Channels