Key result
Pressure overload markedly decreased cardiac Ca2+-ATPase mRNA levels to 32% of sham levels at 1 month, suggesting regulation at the pretranslational level.
Cardiac Ca2+-ATPase expression in the sarcoplasmic reticulum is regulated at the pretranslational level by pressure overload and developmental stage.
Cloned rat cardiac SR Ca2+-ATPase cDNA with 98% amino acid homology to rabbit; extends molecular tools but leaves open clinical relevance.
To investigate the regulation of expression of cardiac Ca2+ + Mg2+-dependent ATPase (Ca2+-ATPase) in sarcoplasmic reticulum (SR), we isolated cDNA (pHA6) encoding a Ca2+-ATPase of rat cardiac SR. The clone consisted of 2,311 mRNA-derived nucleotides, which covered half the coding region and the entire 3'-untranslated regions. The nucleotides and deduced amino acid sequences of pHA6 showed striking homology, 89 and 98%, respectively, to those of rabbit Ca2+-ATPase of the slow-twitch form. Northern blot analyses revealed that the mRNA levels of Ca2+-ATPase were decreased by pressure overload and became 32% of sham in 1 mo. During the developmental stage the mRNA levels were very low in the fetal period and steeply increased around birth. These changes in mRNA levels were correlated with the corresponding protein levels. These results suggest that the expression of cardiac Ca2+-ATPase in SR is regulated by pressure overload and the developmental stage, at least in part, at the pretranslational level.
No takes yet. Share an insight, caveat, or question.
Komuro et al. (1989) studied Cardiac hypertrophy (n=204). Pressure overload (aortic constriction) vs. Sham operation was evaluated on mRNA levels of Ca2+-ATPase (p=<0.001). Pressure overload markedly decreased cardiac Ca2+-ATPase mRNA levels to 32% of sham levels at 1 month, suggesting regulation at the pretranslational level.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: