Abstract
pH-induced closure of connexin43 (Cx43) channels involves interaction of the Cx43 carboxyl-terminal (Cx43CT) with a separate "receptor" domain. The receptor location and structure and whether the interaction is directly intramolecular are unknown. Here we show resonant mirror technology, enzyme-linked sorbent assays, and nuclear magnetic resonance (NMR) experiments demonstrating pH-dependent binding of Cx43CT to region 119-144 of Cx43 (Cx43L2), which we propose is the receptor. NMR showed that acidification induced alpha-helical order in Cx43L2, whereas only a minor modification in Cx43CT structure was detected. These data provide the first demonstration of chemically induced structural order and binding between cytoplasmic connexin domains.
Publication types
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Animals
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Cloning, Molecular
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Connexin 43 / chemistry*
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Connexin 43 / metabolism*
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Cytoplasm / metabolism
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Diffusion
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Dose-Response Relationship, Drug
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Enzyme-Linked Immunosorbent Assay
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Glutathione Transferase / metabolism
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Histidine / chemistry
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Hydrogen Bonding
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Hydrogen-Ion Concentration
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Kinetics
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Magnetic Resonance Spectroscopy
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Molecular Sequence Data
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Peptide Biosynthesis
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Peptides / chemistry
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Protein Binding
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Protein Conformation
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Protein Structure, Tertiary
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Rats
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Recombinant Fusion Proteins / metabolism
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Recombinant Proteins / metabolism
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Time Factors
Substances
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Connexin 43
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Peptides
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Recombinant Fusion Proteins
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Recombinant Proteins
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Histidine
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Glutathione Transferase