Identification and cloning of a truncated isoform of the cardiac sodium-calcium exchanger in the BALB/c mouse heart.
A truncated isoform of the cardiac sodium-calcium exchanger (NCX1) was identified and cloned from BALB/c mouse heart. This cDNA clone has an AATAAA polyadenylation signal in the 3' untranslated region that caused the 3344-bp clone to stop at a premature termination site and encode for a 940-amino acid (AA) protein, in contrast to the wild-type C57BL/6 mouse, which has a 970-AA protein. Comparing the predicted AA sequence of NCX1 between the two mouse strains by hydropathic plot, we found that the BALB/c NCX1 protein has only 11 extracellular domains, missing one domain at the COOH terminal, while C57BL/6 mice have 12 extracellular domains, similar to other species. Using the mouse mapping gene panel BCB, the NCX1 gene was mapped to the distal end of mouse chromosome 17 (51.3 cM), confirming the data published from the rat probe.
Shi
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S
Columbia University, Institute of Comparative Medicine, New York, New York 10032, USA.
Chang
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B
Brunnert
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SR
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D002874:Chromosome Mapping; D002875:Chromosomes / Q000235:genetics*; D003001:Cloning, Molecular; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008969:Molecular Sequence Data; D009206:Myocardium / Q000737:chemistry*; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D019831:Sodium-Calcium Exchanger / Q000235:genetics* / Q000302:isolation & purification
D019831:Sodium-Calcium Exchanger