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Cell Signaling/Gene Reporting
 Living cells constantly adjust to their environment through a complex network of signaling pathways exquisitely regulated in time and space to provide a cell with an integrated exchange of information that is essential for coordinated responses. Hormones, growth factors and neurotransmitters are among the signaling agents that have been the most extensively studied.
Depending upon the nature of these biosignals, distinct pathways are used to enter the cell. For example, hydrophobic compounds such as steroid hormones can proceed through the lipid bilayer of the cells and eventually combine with receptors that are known to be transcription factors regulating gene expression. Upon the binding of agonists to G-protein-coupled receptors, often referred to as seven transmembrane (7TM) domains receptors, second messengers such as cAMP, arachidonic acid, DAG (diacylglycerol) and IP3 (inositol-3-phosphate) are produced within the cell and act as amplificators of the initial signals generated by the primary binding. Other types of external receptors include those with enzymatic activities, such as tyrosine kinase, serine-threonine kinase and tyrosine phosphatase. Mapping of cell signaling systems and establishing their linkages to normal and disease-related processes is therefore a major challenge in developing effective therapeutics for pathological situations. |
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