Human DLL1 APC-conjugated Antibody

Delta-like protein 1 (DLL1) is a 90-100 kDa type I transmembrane protein that belongs to the Delta/Serrate/Lag-2 (DSL) family of Notch ligands. Mature human DLL1 consists of a 528 amino acid (aa) extracellular domain (ECD) with one DSL domain and eight EGF-like repeats, a 23 aa transmembrane segment, and a 155 aa cytoplasmic domain (1). Within the ECD, human DLL1 shares 91% aa sequence identity with mouse and rat DLL1. It shares 26%, 37%, and 54% aa sequence identity with DLL2, 3, and 4, respectively. A 60 kDa ECD fragment released by ADAM9, 12, or 17 mediated proteolysis, promotes the proliferation of hematopoietic progenitor cells (2, 3). The residual membrane-bound portion of DLL1 can be cleaved by presenilin-dependent gamma-secretase, enabling the cytoplasmic domain to migrate to the nucleus (4). DLL1 localizes to adherens junctions on neuronal processes through its association with the scaffolding protein MAGI1 (5). DLL1 is widely expressed, and it plays an important role in embryonic somite formation, cochlear hair cell differentiation, plus B and T lymphocyte differentiation (6-11). The upregulation of DLL1 in arterial endothelial cells following injury or angiogenic stimulation is central to postnatal arteriogenesis (12). DLL1 is also overexpressed in cervical carcinoma and glioma and contributes to tumor progression (1, 13).