Global Protein Quantification of Mouse Heart Tissue Based on the SILAC Mouse

Abstract

Metabolic labeling of living organisms with stable isotopes has become a powerful tool for global protein quantitation. The SILAC (stable isotope labeling with amino acids in cell culture) approach is based on the incorporation of nonradioactive-labeled isotopic forms of amino acids into cellular proteins. The effective SILAC labeling of immortalized cells and single-cell organisms (e.g., yeast and bacteria) was recently extended to more complex organisms, including worms, flies, and even rodents. The administration of a ¹³C₆-lysine (heavy) containing diet for one mouse generation leads to a complete exchange of the natural (light) isotope ¹²C₆-lysine. SILAC-labeled organisms are mainly used as a heavy “spike-in” standard into nonlabeled counterparts, and the combination with high-performance mass spectrometers allows for global proteomic screening. Here we used the fully labeled SILAC mice to identify proteins based on SILAC pairs from isolated cardiomyocytes, and we analyzed β-parvin-deficient hearts. Our approach confirmed the absence β-parvin and revealed simultaneously a clear up regulation of α-parvin in heart tissue. In this protocol, we describe the generation of a SILAC mouse colony and show two approaches to perform a proteome-wide analysis of heart tissue. Thus, the SILAC mouse spike-in approach is a readily available procedure and allows for a straightforward systematic analysis of disease models and knockout mice.