Signaling pathways

Signaling pathways are complex, coordinated series of molecular interactions and chemical reactions that allow cells to perceive and respond to internal and external stimuli (1). These pathways generally begin with the activation of a sensor, such as a cell-surface receptor, which then triggers a cascade of downstream events often involving protein phosphorylation, second messengers, and the activation of transcription factors (2). The primary biological function of these networks is to regulate critical cellular processes, including growth, metabolism, and programmed cell death (3). Dysregulation of signaling pathways is a fundamental driver of many diseases; for example, hyperactivation of the PI3K/Akt/mTOR or MAPK pathways is frequently observed in various cancers (1, 3). In drug discovery, specific components of these pathways, such as tyrosine kinases or G protein-coupled receptors, serve as primary therapeutic targets (2). Because "Signaling pathways" is a broad, collective term rather than a single druggable molecule, it is classified as an incorrect entry for a specific therapeutic target database (1). Understanding the architecture of these pathways is essential for developing precision medicines that can bypass resistance mechanisms or mitigate off-target toxicities (3). Sources: 1. National Human Genome Research Institute (NHGRI). "Signaling Pathway." genome.gov. 2. Nature Education. "Cell Signaling." nature.com/scitable. 3. StatPearls [Internet]. "Signal Transduction." Treasure Island (FL): StatPearls Publishing; 2023.

Other names

Signal transduction pathwaysCell signaling networksBiochemical signaling cascadesIntracellular signaling

Pharmacological agents typically modulate signaling pathways by acting as agonists or antagonists to specific molecular components, such as receptors, kinases, or transcription factors, rather than targeting the pathway as a collective entity.