The processes that use or regulate calcium as a biological signal to transmit information or initiate functions such as exocytosis, synaptic signaling, and contraction are highly developed and specialized for the functional needs of a particular tissue. A large number of cellular proteins have evolved to either recognize, or to transmit biological calcium signals. The signaling between such proteins often occur in confined spaces over distances of a few nano-meters, leaving their detection difficult if not impossible to achieve with present technology. Nevertheless, in the past decade highly sophisticated methods have developed to not only identify the molecular structure of these proteins, and determine the particular motifs involved in recognizing and regulating calcium, but also to critically image the rapid dynamic changes that occur in cellular calcium profiles during exocytosis, synaptic transmission and contraction. One of the major conceptual advances has been the recognition that calcium signaling often occurs in the inter-molecular nano-domains surrounding the signaling protein, rather than in the global cytoplasmic spaces. In effect, the story of calcium signaling is the monitoring and quantification of the cross-talk between cellular proteins of calcium signaling cascade. This book is organized in 5 parts. The first part deals with cardiac and skeletal muscle calcium signaling and their associated proteins. The variability in the regulation of calcium channel is discussed in the second part of the book. In this section a variety of mechanisms that modulate calcium channel, both at the structural and hormonal level have been discussed. Part 3 of the book with calciumsignaling in neurons, and some of the calcium-dependent steps in neuro- as well as pancreatic-secretion. The role of mitochondria in calcium signaling is developed in part 4. The last section of the book presents various other calcium-regulated or calcium-transporting proteins.
