Mouse Notch-1 Alexa Fluor™ Plus 405-conjugated Antibody

Notch-1 is a 300 kDa type I transmembrane glycoprotein that is one of four Notch homologues involved in developmental processes (1‑3). Notch signaling is important for maintaining stem cells and inducing differentiation, especially in the nervous system and lymphoid tissues (2‑4). Notch can specify binary cell fates. For example, it promotes T-cell over B-cell development from a common precursor (2). Mouse Notch-1 is synthesized as a 2531 amino acid (aa) precursor that contains an 18 aa signal sequence, a 1707 aa extracellular domain (ECD) with 36 EGF-like repeats and three Lin-12/notch repeats (LNR), a 21 aa transmembrane (TM) segment and a 785 aa cytoplasmic domain that contains six ankyrin repeats, a glutamine-rich domain and a PEST sequence. The 11^th and 12^th EGF-like repeats, that bind ligands such as Jagged and Delta-like families in humans, correspond to aa 412‑488 in mouse Notch-1 (6). Elongation of O-linked fucose chains by Fringe family members at a site within this region can inhibit the interaction of Notch with Jagged ligands, thereby promoting Delta-like ligand interactions (7). The Notch-1 receptor undergoes post-translational furin-type proteolytic cleavage, generating a heterodimer through the interaction of a hydrophobic area C-terminal to the LNR on the extracellular region with the transmembrane/cytoplasmic portion (8, 9). Upon ligand binding, additional sequential proteolysis by TNF-converting enzyme (ADAM17) and the presenilin-dependent gamma-secretase results in the release of the Notch intracellular domain (NICD) which translocates into the nucleus, activating transcription of Notch-responsive genes (10). Mouse Notch-1 ECD aa 19‑526, which includes the first 13 EGF repeats, shows 94%, 91%, 86% and 79% aa identity with corresponding regions of rat, human, canine, and chicken Notch-1, respectively. This region also exhibits 55‑58% aa identity with human Notch-2 and Notch-3.