Mechanism of MEK1 phosphorylation by the N-terminal acidic motif-mediated asymmetric BRAF dimer.

NtA motif-driven asymmetric BRAF dimerization activates MEK1 phosphorylation, revealing a structural basis for BRAF's role in cancer signaling.

• Why it matters: Understanding BRAF activation mechanisms is crucial because mutations in BRAF are present in 90% of RAF-mutant cancers, yet the structural details of its activation remain unclear.
• What they did: The study used structural and biochemical methods to analyze NtA-mediated BRAF dimers bound to MEK1, demonstrating that NtA is essential for catalytic activity but not for membrane recruitment.
• The result: Findings support a model where NtA-driven asymmetry activates BRAF, bridging gaps between cancer genetics and structural biology, and providing insights into targeted cancer therapies.