Final answer:
When Notch binds with Delta, the cytoplasmic domain of Notch is cleaved and serves as a transcription factor that can regulate the expression of Notch-responsive genes by binding to DNA and interacting with other transcriptional components.
Step-by-step explanation:
When Notch binds Delta, the cytoplasmic domain of Notch is cleaved and becomes a transcription factor for Notch-responsive genes. This process is critical in cellular signaling pathways that dictate cell fate during development. The cleaved intracellular domain of Notch translocates to the nucleus, where it can bind to DNA and regulate gene expression. It interacts with other transcription factors and binds to hormone response elements in the DNA, either activating or repressing transcription of target genes.
The transactivation domain is crucial as it helps to form complexes with other transcription factors that can activate or repress transcription. This is in contrast to the case where a mutation in a transcription factor removes the activation domain, resulting in the inability to activate transcription, leading to reduced levels of gene activation.
Fundamentally, the Notch signaling pathway demonstrates how extracellular signals can dictate gene expression changes by converting a membrane-bound receptor into a transcription factor upon ligand binding and subsequent cleavage.