Cell Signaling : Courses Intended for Master1 Students apllied biochemistry

Abstract

The course Cell Signalling is designed for first-year Master’s students in Applied Biochemistry and provides a comprehensive understanding of the molecular mechanisms that enable cells to communicate with their environment. Cellular communication is essential for the coordination of physiological processes in multicellular organisms and allows cells to perceive, integrate, and respond appropriately to external and internal stimuli. This communication is mediated by a wide variety of signalling molecules, including hormones, neurotransmitters, cytokines, growth factors, and components of the extracellular matrix. These signalling molecules interact with specific receptors located either on the cell surface or within the cell. The binding of a signalling molecule to its receptor initiates a cascade of intracellular events collectively known as signal transduction. Through these mechanisms, extracellular information is converted into specific cellular responses such as gene expression, metabolism regulation, cell proliferation, differentiation, migration, secretion, and apoptosis. The course begins with the fundamental concepts of receptor biology and receptor–ligand interactions, emphasizing receptor specificity, affinity, and signalling mechanisms. It then explores G protein-coupled receptors (GPCRs), one of the largest receptor families involved in cellular communication, and examines the role of heterotrimeric G proteins in signal transmission. Particular attention is given to the major effector pathways activated by G proteins, including the adenylate cyclase/cAMP pathway and the phospholipase C/IP₃/DAG pathway. The course further investigates lipid-mediated signalling pathways involving phospholipase D and phospholipase A₂, highlighting their roles in membrane dynamics, inflammation, and the production of bioactive lipid mediators. Students will also study protein phosphorylation as a fundamental regulatory mechanism, focusing on serine/threonine kinases, protein phosphatases, receptor tyrosine kinases, tyrosine phosphatases, and the molecular processes governing signal amplification and regulation. Special emphasis is placed on Mitogen-Activated Protein Kinase (MAPK) pathways, calcium signalling mechanisms, and intracellular hormone receptors such as estrogen and androgen receptors. The physiological and pathological implications of these signalling systems are discussed throughout the course, providing students with a solid foundation for understanding modern molecular biology, biochemistry, pharmacology, and biomedical research.