Abstract
High voltage-activated Ca(2+) channel expression and gating is controlled by their beta subunits. Although the sites of interaction are known at the atomic level, how beta modulates gating remains to be determined. Using a chimeric approach, beta subunit regulation was conferred to a low voltage-activated channel. Regulation was dependent on a rigid linker connecting the alpha(1) interaction domain to IS6. Chimeric channels also revealed a role for IS6 in channel gating. Taken together, these results support a direct coupling model where beta subunits alter movements in IS6 that occur as the channel transits between closed, open, and inactivated states.
Publication types
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Research Support, N.I.H., Extramural
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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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Biophysical Phenomena
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Biophysics
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Calcium / metabolism
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Calcium Channels / chemistry
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Calcium Channels / metabolism*
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Calcium Channels, N-Type / immunology
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Calcium Channels, T-Type / immunology
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Cell Line
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Circular Dichroism
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Electrophysiology
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Green Fluorescent Proteins / metabolism
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Humans
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Kinetics
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Molecular Sequence Data
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Protein Structure, Tertiary
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Rats
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Recombinant Fusion Proteins / chemistry
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Sequence Homology, Amino Acid
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Structure-Activity Relationship
Substances
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Calcium Channels
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Calcium Channels, N-Type
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Calcium Channels, T-Type
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Recombinant Fusion Proteins
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Green Fluorescent Proteins
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Calcium