MEK (Mitogen-Activated Protein Kinase)

MEK, or Mitogen-Activated Protein Kinase Kinase, is an enzyme involved in cell signaling, acting as a relay in pathways that control cell growth, division, and survival. It is part of the MAPK/ERK pathway, which transmits signals from the cell surface to the nucleus in response to various stimuli. When activated, MEK phosphorylates specific proteins, leading to changes in gene expression and cell behavior. Proper regulation of MEK is essential for normal cell functions, while its abnormal activity can contribute to diseases like cancer by promoting uncontrolled cell growth.