Mitogen-activated protein kinase kinase–Kinase suppressor of ras protein–protein interface (MEK–KSR interface)

The Mitogen-activated protein kinase kinase–Kinase suppressor of ras (MEK–KSR) protein–protein interface is a vital regulatory component of the Ras-Raf-MEK-ERK signaling pathway (Brennan et al., 2011, Nature). Kinase Suppressor of Ras (KSR) acts as a molecular scaffold that facilitates the assembly and activation of the MAPK cascade by bringing MEK into proximity with its upstream activator, RAF, and its downstream substrate, ERK (UniProt Q8IVT5). This interface is particularly significant in oncogenesis, as hyperactivation of the MAPK pathway is a hallmark of cancers driven by KRAS, NRAS, or BRAF mutations (Khan et al., 2020, Cell Chemical Biology). Therapeutic targeting of this interface aims to disrupt the scaffold-mediated signaling that often bypasses traditional kinase inhibitors. Notably, the MEK inhibitor Trametinib has been shown to bind to MEK specifically when it is in complex with KSR, highlighting the interface's importance for drug efficacy (Lavoie et al., 2018, Nature). Emerging strategies focus on small molecules that either disrupt the KSR-MEK interaction or allosterically inhibit the complex to overcome resistance in RAS-mutant malignancies.

Other names

KSR-MEK complexMEK-KSR heterodimerKinase suppressor of ras-Mitogen-activated protein kinase kinase interfaceKSR-MEK interaction

Allosteric inhibition of MEK within the KSR scaffold and disruption of the KSR-mediated assembly of the RAF-MEK-ERK signaling complex.