Cellular behavior,rather than the function of one or a few molecules,is an emergent property of an interconnected network of proteins,nucleotides,metabolites and other molecules.To understand this emergence,one must understand how large sets of molecules relate to each other to engender phenotype.Our group is focused on the complex phenotypic state of heart disease,a leading cause of morbidity and mortality worldwide.Specifically,we are using proteomics/mass spectrometry to deconvolute protein interaction networks and examine the post-translational modifications (e.g.phosphorylation) responsible for information flow through these networks.Biochemistry and molecular biology approaches are used to functionally define relationships among groups of proteins in different sectors of the network.Integration of these different levels of information is done via bioinformatics.Mathematical modeling is used to reveal novel dynamical relationships within the network as a whole.Lastly,the effects of disease (such as acute myocardial infarction and heart failure) on the behavior of protein interaction networks is examined at the whole animal and proteomic level.The objective of this approach is to gain a systems level understanding of the reprogramming of intracellular networks responsible for death or survival.