Structure of the rabbit fast-twitch skeletal muscle calsequestrin gene.

We have isolated two overlapping 17-kilobase (kb) genomic clones which, together, encode the rabbit fast-twitch skeletal muscle calsequestrin. The calsequestrin gene is 8.6 kb in length and consists of 11 exons. S1 nuclease protection and primer extension analyses position the transcription initiation site 191 nucleotides upstream of the translation initiation codon. The 5'-flanking sequence contains a CCAAT sequence and two CG-rich sequences but does not have an identifiable TATA box sequence in the anticipated position just upstream of the transcription initiation site. The sequence of the calsequestrin gene confirmed the sequence deduced from cDNA clones derived from neonatal muscle mRNA (Fliegel, L., Ohnishi, M., Carpenter, M. R., Khanna, V. K., Reithmeier, R. A. F., and MacLennan, D. H. (1987) Proc. Natl. Acad. Sci. U. S. A. 84, 1167-1171). We could not detect any potential alternative splicing of the transcript in an analysis of this region of the gene that would account for the different sequence found at the carboxyl terminus of adult rabbit fast-twitch skeletal muscle calsequestrin.