Abstract
Reversible, covalent modification with small ubiquitin-related modifier proteins (SUMOs) is known to mediate nuclear import/export and activity of transcription factors. Here, the SUMO pathway is shown to operate at the plasma membrane to control ion channel function. SUMO-conjugating enzyme is seen to be resident in plasma membrane, to assemble with K2P1, and to modify K2P1 lysine 274. K2P1 had not previously shown function despite mRNA expression in heart, brain, and kidney and sequence features like other two-P loop K+ leak (K2P) pores that control activity of excitable cells. Removal of the peptide adduct by SUMO protease reveals K2P1 to be a K+-selective, pH-sensitive, openly rectifying channel regulated by reversible peptide linkage.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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COS Cells
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Cell Membrane / metabolism*
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Cell Membrane / physiology
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Chlorocebus aethiops
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Cysteine Endopeptidases
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Electrophysiology
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Endopeptidases / metabolism
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Humans
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Hydrogen-Ion Concentration
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Ion Channel Gating / physiology*
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Mutation / genetics
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Oocytes / metabolism
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Oocytes / physiology
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Peptides / metabolism
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Potassium Channels, Tandem Pore Domain / physiology*
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Protein Binding
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Small Ubiquitin-Related Modifier Proteins / metabolism*
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Two-Hybrid System Techniques
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Xenopus Proteins / metabolism
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Xenopus laevis
Substances
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Peptides
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Potassium Channels, Tandem Pore Domain
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Small Ubiquitin-Related Modifier Proteins
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Xenopus Proteins
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Endopeptidases
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SENP1 protein, human
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Cysteine Endopeptidases