Regulation of Notch Signaling in Drosophila melanogaster: The Role of the Heterogeneous Nuclear Ribonucleoprotein Hrp48 and Deltex.

Notch signaling is an evolutionarily conserved pathway that plays a central role in a number of cellular events during metazoan development. Due to its involvement in numerous developmental events, Notch signaling requires tight spatial and temporal regulation. Deltex is a cytoplasmic protein that physically binds to the Notch and regulates its signaling activity in a context-dependent manner. However, the biology of Deltex in regulation of Notch signaling is not well explored. For a better understanding of Deltex activity in the regulatory circuit of Notch pathway, a co-IP-based screening was performed. Hrp48, an RNA-binding protein, was identified as an interacting partner of Deltex in that screening. Interaction of these two proteins seemed to regulate the Notch signaling outcome in the epithelial tissue. Additionally, it was found that coexpression of Deltex and Hrp48 can lead to cell death as well as JNK activation. Considering the fact of well conserved nature of Notch as well as both of these two proteins, namely, Hrp48 and Deltex, this interaction can be helpful to understand the regulation of Notch signaling both in development and disease condition.