Tissue-specific expression of two human Ca(v)1.2 isoforms under the control of distinct 5' flanking regulatory elements.
Transcriptional regulation may be important for L-type Ca(2+) channel alpha(1C) subunit (Ca(v)1.2) gene expression. In this study, we found two human Ca(v)1.2 isoforms, one strongly and selectively expressed in heart and the other with apparently ubiquitous expression. The promoter for the cardiac isoform has an 'initiator' sequence, and is active in neonatal cardiomyocytes but not in cardiac fibroblasts, H9C2 cells, human aorta-vascular smooth muscle and HEK293 cells. The promoter for the ubiquitously expressed isoform is of the 'housekeeping' type and is active in all cell types examined. These data indicate specific expression patterns of two human Ca(v)1.2 isoforms under the control of distinct 5' flanking regulatory sequences.
Pang
Li
L
Department of Medicine, Montreal Heart Institute, and University of Montreal, 5000 Belanger St East, Montreal, QC, Canada H1T 1C8.
Koren
Gideon
G
Wang
Zhiguo
Z
Nattel
Stanley
S
D000818:Animals; D001483:Base Sequence; D020746:Calcium Channels, L-Type / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002478:Cells, Cultured; D017931:DNA Primers; D018076:DNA, Complementary; D006801:Humans; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid
D020746:Calcium Channels, L-Type; D017931:DNA Primers; D018076:DNA, Complementary; C419385:L-type calcium channel alpha(1C); D020033:Protein Isoforms