Structure and functional expression of a member of the low voltage-activated calcium channel family.
Oscillatory firing patterns are an intrinsic property of some neurons and have an important function in information processing. In some cells, low voltage-activated calcium channels have been proposed to underlie a depolarizing potential that regulates bursting. The sequence of a rat brain calcium channel alpha 1 subunit (rbE-II) was deduced. Although it is structurally related to high voltage-activated calcium channels, the rbE-II channel transiently activated at negative membrane potentials, required a strong hyperpolarization to deinactivate, and was highly sensitive to block by nickel. In situ hybridization showed that rbE-II messenger RNA is expressed in regions throughout the central nervous system. The electrophysiological properties of the rbE-II current are consistent with a type of low voltage-activated calcium channel that requires membrane hyperpolarization for maximal activity, which suggests that rbE-II may be involved in the modulation of firing patterns.
Biotechnology Laboratory, University of British Columbia, Vancouver, Canada.
T W
TW
Soong
A
A
Stea
C D
CD
Hodson
S J
SJ
Dubel
S R
SR
Vincent
T P
TP
Snutch
D000595:Amino Acid Sequence; D000818:Animals; D001923:Brain Chemistry; D015220:Calcium Channels / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D020908:Calcium Channels, R-Type; D027682:Cation Transport Proteins; D003001:Cloning, Molecular; D004553:Electric Conductivity; D006624:Hippocampus / Q000737:chemistry; D017403:In Situ Hybridization; D008564:Membrane Potentials; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000502:physiology; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D051381:Rats; D016415:Sequence Alignment
C498917:Cacna1e protein, rat; D015220:Calcium Channels; D020908:Calcium Channels, R-Type; D027682:Cation Transport Proteins; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger