Signalkaskader

Signalkaskader is a term used in molecular and cellular biology to describe the sequential series of biochemical events that transmit information from a cell’s surface receptors to intracellular targets, ultimately producing a specific cellular response. In this concept, signals are relayed through multiple components such as kinases, adaptors, and second messengers, creating a cascade that can amplify and shape the final outcome.

A typical signalkaskad starts with an extracellular signal binding to a receptor (for example, a receptor tyrosine kinase or a G protein–coupled receptor). This event activates intracellular relay proteins and second messengers, propagating the signal through successive tiers of proteins, including kinases and transcription factors. Specificity is achieved through scaffolding proteins and spatial organization within the cell, while amplification allows a small initial signal to generate a large response. Regulation occurs via feedback loops and phosphatases that terminate the signal or modulate its duration and intensity.

Biological significance of signalkaskader is broad, encompassing development, cell growth, metabolism, immune responses, and homeostasis. Dysregulation or mutation of signaling cascades is associated with diseases such as cancer, diabetes, and neurodegenerative conditions. Researchers study these cascades using biochemical assays, live-cell imaging, fluorescence resonance energy transfer (FRET), genetics, and computational modeling to understand dynamics, cross-talk between pathways, and potential therapeutic targets.

The term is widely used in Scandinavian literature and is often synonymous with the broader concept of signal transduction cascades in English.