Connector enhancer of kinase suppressor of ras 1 (CNKSR1) (CNKSR1)

Connector enhancer of kinase suppressor of ras 1 (CNKSR1) is a multidomain scaffold protein that plays a pivotal role in coordinating intracellular signaling, particularly within the Ras/MAPK, PI3K/AKT, and Rho GTPase pathways. It contains a Pleckstrin Homology (PH) domain that mediates its recruitment to the plasma membrane by binding to phosphoinositides like phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2). In many cancers, especially those driven by mutant KRAS, CNKSR1 is overexpressed and facilitates the assembly of oncogenic signaling complexes at the cell membrane, promoting tumor cell proliferation, survival, and invasion. The PH domain has emerged as a viable therapeutic target; small molecules such as PHT-7.3 have been developed to selectively bind this domain, thereby preventing CNKSR1 membrane localization and disrupting its interaction with mutant KRAS. Furthermore, CNKSR1 has been identified as a key mediator of adaptive resistance to MEK inhibitors by facilitating compensatory AKT activation. Beyond its role in oncology, loss-of-function mutations in CNKSR1 are associated with syndromic intellectual disability, highlighting its essential function in neural development and brain architecture.

Other names

CNK1CNKConnector enhancer of KSR 1Connector enhancer of KSR-like

Inhibition of the PH domain prevents plasma membrane localization and disrupts the scaffolding of mutant KRAS signaling complexes, thereby blocking downstream MAPK and AKT pathways.