Mitogen-activated protein kinase signaling pathway (Ras-Raf-MEK-ERK pathway) (MAPK pathway (also called ERK pathway or Ras-Raf-MEK-ERK pathway))

The MAPK/ERK pathway (Ras-Raf-MEK-ERK pathway) is a central signal transduction cascade in eukaryotic cells, critical for transmitting extracellular growth signals to the nucleus via a sequence of phosphorylation events. It begins with activation of a cell surface receptor (often a receptor tyrosine kinase), leading to recruitment and activation of small GTPases such as Ras. Active Ras then stimulates a cascade of serine/threonine kinases — Raf (MAP3K) ➔ MEK1/2 (MAP2K) ➔ ERK1/2 (MAPK). Activated ERK translocates to the nucleus to regulate gene expression controlling cell proliferation, differentiation, and survival. Dysregulation of this pathway, particularly through oncogenic mutations in Ras or BRAF, is implicated in numerous cancers and developmental syndromes.

Other names

MAPK/ERK pathwayRas-Raf-MEK-ERK pathwayMAPK cascadeRas-MAPK pathway

Inhibit kinase activity (e.g., BRAF or MEK inhibitors prevent downstream signaling) Block mutant Ras protein function (e.g., direct KRAS G12C inhibition) Modulate pathway activation at the receptor or GTPase level