Nucleolin is a multi-functional protein that is one of the major components of the nucleoli. It contains four RNA binding domains that interact with pre-rRNA during synthesis. Nucleolin can influence RNA processing, ribosomal gene transcription and nucleolar targeting of ribosomal components. While the main function of Nucleolin is ribosome biogenesis, it plays an important role in various other nuclear activities. Down regulation of Nucleolin leads to increased expression of p53, defects in genome duplication, and a delay at prometaphase during mitosis leading to cell cycle arrest.
