Casq2 deletion causes sarcoplasmic reticulum volume increase, premature Ca²⁺ release, and catecholaminergic polymorphic ventricular tachycardia
J. Clin. Invest. Björn C. Knollmann, et al. 116:2510 doi:10.1172/JCI29128 [Go to this article.]

Figure 1
Generating the Casq2^– allele. (A) The Casq2 exon 1 sequence as determined by 5′ RACE. Four transcriptional starts were identified and are marked with filled arrowheads. Nucleotide number 1 represents the 5′ end of the longest identified transcript. Exon 1 includes 3 in-frame ATG translational starts (underlined). Only the second ATG is conserved in other vertebrates, and only this ATG is predicted to encode a leader sequence that would appropriately target the nascent CASQ2 peptide to the SR. (B) Wild-type (i) and mutant (ii) alleles of the Casq2 locus are depicted. The Casq2 locus spans more than 60 kb and includes 11 exons (vertical bars). Exon 1 encodes the ATG initiation codon and the first 78 amino acids. The Casq2^– allele is a 1.1-kb deletion that removes 561 bp of upstream sequences, including the presumptive Casq2 promoter (open oval) as well as the entire 431-bp exon 1 and 107 bp of intron 1.