A Membrane Bounded Organelle of Eukaryotic Cells in Which Chromosomes Are Housed and Replicated. in Most Cells the Nucleus Contains All of the Cell's Chromosomes Except the Organellar Chromosomes and Is the Site of RNA Synthesis and Processing. in Some Species or in Specialized Cell Types RNA Metabolism or DNA Replication May Be Absent.
Combining with Retinoic Acid and Transmitting the Signal to the Transcriptional Machinery by Interacting Selectively and Non Covalently with a Specific DNA Sequence in Order to Modulate Transcription by RNA Polymerase Ii. Retinoic Acid Is One of the Forms of Vitamin A.