Cell Signalling

Cell signalling encompasses the entire cascade of molecular events by which cells communicate with each other and their environment, from initial signal reception to final cellular response. It typically involves a signalling molecule (ligand) such as a peptide hormone binding to a receptor, which triggers intracellular signal transduction pathways involving kinases, second messengers (cAMP, calcium, IP3), and transcription factors that ultimately alter gene expression or cell behaviour. Peptides are among the most important signalling molecules in biology, acting as hormones, neurotransmitters, and growth factors. For example, GLP-1 and GIP bind to their respective G-protein-coupled receptors to initiate signalling cascades that regulate insulin secretion and metabolism. Understanding cell signalling pathways is essential for interpreting how research peptides exert their biological effects.