Screening for novel calcium-binding proteins that regulate cardiac hypertrophy: CIB1 as an example

Abstract

Calcium-binding proteins have a crucial function in the regulation of cardiac contractility as well as in the regulation of cardiac signal-transduction. Because they sense calcium concentrations and at the same time bind specific signaling molecules, some of these proteins are critically involved in the establishment of signaling microdomains, which are insulated from the large cytosolic calcium fluctuations involved in cardiac excitation–contraction coupling. In this regard, we have recently identified the calcium-binding protein CIB1 as an important regulator of pathological cardiac hypertrophy and transition to heart failure. It is almost certain that more, currently unknown calcium-binding proteins with similar regulatory function in cardiac signaling exist. Here, I suggest screening strategies to identify these calcium-binding proteins with impact on cardiac hypertrophy and provide a detailed protocol for the identification of protein interaction partners. I also describe cell culture-based models for cardiomyocyte hypertrophy as well as mouse models for pathological or physiological hypertrophy and strategies to analyze the impact of candidate genes on the development of hypertrophy.