KRAS Screening & Profiling Services

KRAS is an important protein in the RAS/MAPK signaling pathway that transmits signals from activated cell surface receptors leading to cell proliferation and survival. KRAS function is controlled by cycling through an inactive, GDP-bound state and an active, GTP-bound state. Activation of KRAS occurs when it binds to Guanine Nucleotide Exchange Factor (GEF) proteins, including SOS, which initiate the exchange of GDP for GTP. Active, GTP-bound KRAS can trigger activation of downstream signaling molecules including RAF, PI3K, and RAL. KRAS can self-inactivate by cleaving the terminal phosphate group on the GTP, converting it to GDP. This inactivation process is accelerated by GTPase-activating (GAP) proteins.

KRAS has emerged as a target of significant clinical interest, due to mutations in the KRAS protein that promote the pathogenesis of 20-30% of human cancers. Testing a patient for the presence of specific KRAS mutants serves as a highly predictive marker for success rates to various types of lung and colon cancer therapies. The development of inhibitors against KRAS G12C, G12D, and G12V holds a promising future for oncology.

Fluorogenic Nucleotide Exchange Assay

Fluorogenic Nucleotide Exchange Assays are homogeneous assays designed for the screening and profiling of KRAS antagonists/inhibitors. In this assay, KRAS is pre-loaded with fluorescent BODIPY-GDP. Adding GTP in the presence of EDTA displaces BODIPY-GDP. The fluorescence intensity decreases as the BODIPY-GDP is displaced by GTP. Several KRAS inhibitors lock KRAS in the (inactive) GDP-bound conformation and prevent GDP/GTP exchange. In this scenario, the fluorescence intensity increases with drug concentration as more BODIPY-GDP remains bound to KRAS.