Neurogenic locus notch homolog protein 1 (Notch receptor 1) (NOTCH1)

Neurogenic locus notch homolog protein 1 (Notch receptor 1) is a highly conserved single-pass transmembrane receptor that plays a pivotal role in cell fate determination, proliferation, and apoptosis through juxtacrine signaling. Upon ligand binding by Delta-like or Jagged ligands, the receptor undergoes sequential proteolytic cleavages, the final being mediated by the gamma-secretase complex, which releases the Notch intracellular domain (NICD). The NICD then translocates to the nucleus to act as a transcriptional activator for target genes such as HES1 and MYC. Notch 1 is a well-established oncogene in T-cell acute lymphoblastic leukemia (T-ALL), where gain-of-function mutations are found in over 50% of cases, and it is also implicated in the progression of various solid tumors, including breast, lung, and pancreatic cancers. Conversely, in certain contexts such as the skin and endothelium, Notch 1 can act as a tumor suppressor, and its chronic inhibition has been linked to the development of vascular neoplasms. Therapeutic strategies have historically focused on gamma-secretase inhibitors (GSIs), though their clinical utility has been limited by significant gastrointestinal toxicity resulting from pan-Notch inhibition. Recent advancements include the development of paralog-specific monoclonal antibodies and small molecule inhibitors of the Notch transcriptional complex to improve the therapeutic window and reduce off-target effects.

Other names

NOTCH1TAN1Translocation-associated notch protein TAN-1hN1AOS5AOVD1Neurogenic locus notch homolog protein 1

Drugs targeting Notch 1 primarily inhibit the proteolytic cleavage events required for receptor activation. Gamma-secretase inhibitors (GSIs) block the intramembrane cleavage of the receptor, preventing the release of the Notch intracellular domain (NICD) and subsequent transcriptional activation. Monoclonal antibodies target the extracellular domain to block ligand binding or to stabilize the negative regulatory region (NRR), thereby preventing the conformational changes necessary for proteolytic processing. Emerging therapies also include small molecules that disrupt the assembly of the Notch transcription complex in the nucleus.