|DLL1 in Embryonic Mouse Kidney. DLL1 was detected in immersion fixed frozen sections of embryonic mouse kidney (E13.5) using 10 µg/mL Sheep Anti-Mouse/Rat DLL1 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF5026) overnight at 4 °C. Tissue was stained with the NorthernLights™ 557-conjugated Anti-Sheep IgG Secondary Antibody (red, upper panel; Catalog # NL010) and counterstained with DAPI (blue, lower panel). View our protocol for Fluorescent IHC Staining of Frozen Tissue Sections.|
Delta-like protein 1 (DLL1) is a 90‑100 kDa type I transmembrane protein in the Delta/Serrate/Lag-2 (DSL) family of Notch ligands. Mature mouse 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 154 aa cytoplasmic domain (1). Within the ECD, mouse DLL1 shares 91% and 95% aa sequence identity with human and rat DLL1, respectively. It shares 26%, 35%, and 51% 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, lymphocyte differentiation, and the maintenance of neural and myogenic progenitor cells (6‑12). The upregulation of DLL1 in arterial endothelial cells following injury or angiogenic stimulation is central to postnatal arteriogenesis (13). DLL1 is also overexpressed in cervical carcinoma and glioma and contributes to tumor progression (14‑15).