Notch transcription. Molecular model showing a strand of DNA (deoxyribonucleic acid) being acted upon by various proteins and other molecules. The main proteins are transcription factor CSL (blue) and the Notch 1 intra-cellular receptor or domain (white). Both are bound to a specific DNA sequence named HES1 promoter (Hairy and Enhancer of Split-1). The CSL-Notch interaction is stabilized by interaction with transcriptional co-activator Mastermind-like protein (MAML, orange, lower left). This transcription process is part of a wider cell signalling system called the notch signalling pathway.