Characterization of the 3′ end of the mouse SERCA 3 gene and tissue distribution of mRNA spliced variants1

The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) type 1 and 2 genes are alternatively spliced at their 3′ end. We hypothesized that similar mechanism may occur for SERCA 3. Two spliced variants were identified by RNase protection analysis. We then isolated and sequenced the 3′ end portion of the mouse SERCA 3 gene, and confirmed the presence of an alternative mRNA transcript by sequencing a cDNA fragment obtained by RT-PCR. Tissue distribution of the alternatively spliced mRNAs was studied by RT-PCR: SERCA 3b was the only isoform expressed in endothelial cells from aorta and heart and also was the major isoform in lung and kidney whereas SERCA 3a and 3b were coexpressed in trachea, intestine, thymus, spleen, and fetal liver.