Human skeletal muscle calcium channel alpha1S is expressed in the basal ganglia: distinctive expression pattern among L-type Ca2+ channels.
Voltage-gated calcium channels (VGCCs) are essential molecules for neuronal function. VGCCs consist of five subunits, alpha1, alpha2, beta, gamma, and delta. Among the ten subtypes of the alpha1 subunit (alpha1A-I and S), expression of alpha1S was previously believed to be restricted to the skeletal muscle. We report here, however, that alpha1S is also expressed in human and rat central nervous system. First, we performed PCR screening for VGCC alpha1 subunits in human nervous system using degenerate primers, and identified alpha1S as well as all the eight alpha1 subunits with previously described expression. Intriguingly, alpha1S was selectively localized to the basal ganglia, particularly the caudate nucleus. In situ hybridization showed that alpha1S was expressed in medium-sized caudate neurons. Quantitative analysis using real time RT-PCR revealed a distinct pattern of alpha1S expression among L-type calcium channels. Furthermore, RT-PCR using laser-mediated manipulation of single cells suggested that human alpha1S was coexpressed with ryanodine receptors (RYRs) in GABAergic neurons. Our results suggest the potential relevance of alpha1S to dopaminergic signal transduction and calcium-induced calcium release in caudate neurons.
Takahashi
Yuji
Y
Department of Neurology, Graduate School of Medicine, The University of Tokyo, Bunkyo-ku, Tokyo 113-8655, Japan.
Jeong
Seon-Yong
SY
Ogata
Katsuhisa
K
Goto
Jun
J
Hashida
Hideji
H
Isahara
Kyoko
K
Uchiyama
Yasuo
Y
Kanazawa
Ichiro
I
D000818:Animals; D001479:Basal Ganglia / Q000378:metabolism*; D015152:Blotting, Northern; D015220:Calcium Channels / Q000096:biosynthesis*; D020746:Calcium Channels, L-Type / Q000378:metabolism; D006801:Humans; D017403:In Situ Hybridization; D018482:Muscle, Skeletal / Q000502:physiology; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019837:Ryanodine Receptor Calcium Release Channel / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D015220:Calcium Channels; D020746:Calcium Channels, L-Type; D019837:Ryanodine Receptor Calcium Release Channel; D005680:gamma-Aminobutyric Acid