Molecular interactions between the protein products of the neurogenic loci Notch and Delta, two EGF-homologous genes in Drosophila

TLDR

Genetic analyses suggest that the transmembrane proteins encoded by the neurogenic loci Notch and Delta may interact. The study investigates whether Notch and Delta proteins associate intermolecularly. The authors expressed Notch and Delta in Drosophila S2 cells and examined aggregation. Notch-expressing cells form calcium‑dependent mixed aggregates with Delta-expressing cells, and Notch and Delta associate within the same cell membrane, forming detergent‑soluble extracellular domain complexes.

Abstract

Genetic analyses have raised the possibility of interactions between the gene products of the neurogenic loci Notch and Delta, each of which encodes a transmembrane protein with EGF homology. To examine the possibility of intermolecular association between the products of these two genes, we studied the effects of their expression on aggregation in Drosophila S2 cells. We find that Notch-expressing cells form mixed aggregates specifically with cells that express Delta and that this process is calcium dependent. In addition, we show that Notch and Delta can associate within the membrane of a single cell, and further, that they form detergent-soluble intermolecular complexes. Our analyses suggest that Notch and Delta proteins interact at the cell surface via their extracellular domains.