Chapter 13 - Cell signaling and apoptosis in animals

Abstract

Cell signaling and apoptosis play a vital role in the execution of a plethora of events in cellular systems. Cell signaling operates cells to respond in an appropriate manner to specific stimuli, and thereby, regulates the cellular function effectively. Cell signaling conquers difficulties in animal growth and developments through the mechanism of autocrine, paracrine, endocrine, direct contact signals. Intensive efforts have been made to explore the molecular mechanism of cell signaling, including signaling receptors, intracellular signaling, and surface receptors (GPCRs, ligand-gated on channels, enzyme-linked receptors, RTKs). The role of second messengers in animal cell signaling, types, and mechanism in amplifying the signals viz WNT signaling, NF-kB, Nitric oxide, and Nuclear receptor pathways and their role in regulating the animal cell signaling is being highlighted. In addition, the strategies of computational mapping of cell signaling pathways are discussed. A tightly regulated process of apoptosis is profoundly important to maintain the cell population during the development and maturation as part of a physiological mechanism. In this chapter, the classification of apoptosis in animals, including intrinsic and extrinsic apoptosis pathways, are highlighted. Also, the regulatory mechanism in animal cells, apoptosis deregulation, and diseases are briefly discussed. Hence, studying cell signaling and apoptosis to understand the mechanism of diseased cell states facilitates in targeting the pathogenesis of the particular disease, and it further directs in framing therapeutic modalities to cure abnormalities through proper disease diagnosis.