Unraveling the secrets of a double life: Contractile versus signaling Ca2+ in a cardiac myocyte

• Published in: Journal of molecular and cellular cardiology 2012-02, Vol.52 (2), p.317-322
• Main Authors: Goonasekera, Sanjeewa A, Molkentin, Jeffery D
• Format: Article
• Language: English
• Subjects: Animals; Calcium; Calcium - metabolism; Calcium Signaling - physiology; Cardiomegaly - metabolism; Cardiovascular; Contraction; Heart; Humans; Hypertrophy; Myocardial Contraction - physiology; Myocytes, Cardiac - metabolism; Signaling
• ISSN: 0022-2828; 1095-8584
• DOI: 10.1016/j.yjmcc.2011.05.001

Abstract No other inorganic molecule known in biology is considered as versatile as Ca2+ . In a vast majority of cell types, Ca2+ acts as a universal second messenger underlying critical cellular processes varying from gene transcription to cell death. Although the role of Ca2+ in myocyte contraction has been known for over a century, it was only more recently that this divalent cation has been implicated in mediating reactive signal transduction to promote cardiac hypertrophy. However, it remains unclear how Ca2+ -dependent signaling pathways are regulated/activated in a cardiac myocyte given the prevailing conditions throughout the cytosol where Ca2+ concentration oscillates between 100 nM and upwards of 1–2 μM during each contractile cycle. In this review we will examine three hypotheses put forward to explain how Ca2+ might still function as a hypertrophic signaling molecule in cardiac myocytes and discuss the current literature that supports each of these views. This article is part of a special issue entitled “Local Signaling in Myocytes.”