Walklate Jonathan, Ferrantini Cecilia, Johnson Chloe A, Tesi Chiara, Poggesi Corrado, Geeves Michael A
Division of Natural Sciences, School of Biosciences, University of Kent, Canterbury, CT2 7NJ, UK.
Department of Experimental and Clinical Medicine, University of Florence, Florence, Italy.
Cell Mol Life Sci. 2021 Dec;78(23):7309-7337. doi: 10.1007/s00018-021-03971-y. Epub 2021 Oct 26.
Human atrial and ventricular contractions have distinct mechanical characteristics including speed of contraction, volume of blood delivered and the range of pressure generated. Notably, the ventricle expresses predominantly β-cardiac myosin while the atrium expresses mostly the α-isoform. In recent years exploration of the properties of pure α- & β-myosin isoforms have been possible in solution, in isolated myocytes and myofibrils. This allows us to consider the extent to which the atrial vs ventricular mechanical characteristics are defined by the myosin isoform expressed, and how the isoform properties are matched to their physiological roles. To do this we Outline the essential feature of atrial and ventricular contraction; Explore the molecular structural and functional characteristics of the two myosin isoforms; Describe the contractile behaviour of myocytes and myofibrils expressing a single myosin isoform; Finally we outline the outstanding problems in defining the differences between the atria and ventricles. This allowed us consider what features of contraction can and cannot be ascribed to the myosin isoforms present in the atria and ventricles.
人的心房和心室收缩具有不同的机械特性，包括收缩速度、输送的血液量以及产生的压力范围。值得注意的是，心室主要表达β-心肌肌球蛋白，而心房主要表达α-异构体。近年来，在溶液中、分离的心肌细胞和肌原纤维中，对纯α-和β-肌球蛋白异构体的特性进行探索已成为可能。这使我们能够考虑心房与心室的机械特性在多大程度上由所表达的肌球蛋白异构体决定，以及异构体特性如何与其生理作用相匹配。为此，我们概述心房和心室收缩的基本特征；探索两种肌球蛋白异构体的分子结构和功能特性；描述表达单一肌球蛋白异构体的心肌细胞和肌原纤维的收缩行为；最后，我们概述在界定心房和心室差异方面存在的突出问题。这使我们能够考虑哪些收缩特征可以以及不能归因于心房和心室中存在的肌球蛋白异构体。
