Expression of multiple CaV1.2 transcripts in rat tissues mediated by different promoters.
The expression of two different transcripts for Ca(V)1.2 in rat tissues mirrors that which has previously been described for human tissue, in that expression of transcripts expressing exon 1a is predominant only in heart, whereas expression of transcripts expressing exon 1b is greater in smooth muscle rich tissues such as aorta and intestine. Transcripts expressing exon 1b also predominate in brain and in diaphragm. Western blots indicate that the N-terminus coded for by exon 1b is present in much of the protein in all these tissues except heart. The promoter just upstream of exon 1b has been cloned, sequenced and utilized to drive expression of luciferase in smooth muscle A7r5 cells, cardiac HL-1 cells, skeletal muscle L6 cells and neuronal PC12 cells. The nucleotide sequence of the promoter exhibits 80% identity with the equivalent promoter previously identified in humans and 94% identity with the sequence of the equivalent region of the mouse genome. Evidence in favor of still another promoter upstream of exon 2 has been uncovered.
Saada
Nehad I
NI
Department of Neuroscience and Cell Biology, University of Texas Medical Branch, Galveston, TX 77555-0641, USA.
Carrillo
Elba D
ED
Dai
Bosong
B
Wang
Wen-Ze
WZ
Dettbarn
Christine
C
Sanchez
Jorge
J
Palade
Philip
P
D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000096:biosynthesis*; D003964:Diaphragm / Q000378:metabolism; D005091:Exons; D015870:Gene Expression; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000378:metabolism; D009206:Myocardium / Q000378:metabolism; D016716:PC12 Cells; D011401:Promoter Regions, Genetic; D051381:Rats; D017207:Rats, Sprague-Dawley; D017208:Rats, Wistar; D017422:Sequence Analysis, DNA
D020746:Calcium Channels, L-Type; C419385:L-type calcium channel alpha(1C)