PT  - JOURNAL ARTICLE
AU  - Dejian Ren
AU  - Hongjian Xu
AU  - Daniel F. Eberl
AU  - Maninder Chopra
AU  - Linda M. Hall
TI  - A Mutation Affecting Dihydropyridine-Sensitive Current Levels and Activation Kinetics in <em>Drosophila</em> Muscle and Mammalian Heart Calcium Channels
AID  - 10.1523/JNEUROSCI.18-07-02335.1998
DP  - 1998 Apr 01
TA  - The Journal of Neuroscience
PG  - 2335--2341
VI  - 18
IP  - 7
4099  - http://www.jneurosci.org/content/18/7/2335.short
4100  - http://www.jneurosci.org/content/18/7/2335.full
SO  - J. Neurosci.1998 Apr 01; 18
AB  - The Dmca1D gene encodes a Drosophilacalcium channel α1 subunit. We describe the first functional characterization of a mutation in this gene. This α1 subunit mediates the dihydropyridine-sensitive calcium channel current in larval muscle but does not contribute to the amiloride-sensitive current in that tissue. A mutation, which changes a highly conserved Cys to Tyr in transmembrane domain IS1, identifies a residue important for channel function not only inDrosophila muscle but also in mammalian cardiac channels. In both cases, mutations in this Cys residue slow channel activation and reduce expressed currents. Amino acid substitutions at this Cys position in the cardiac α1 subunit show that the size of the side chain, rather than its ability to form disulfide bonds, affects channel activation.