| Modification Notes |
NREBP (negative regulatory element-binding protein), also known as SON, SON3, BASS1 or DBP-5, is a 2426 amino acid nuclear speckle protein that is widely expressed, with highest expression in leukocyte and heart. NREBP binds to a specific DNA sequence upstream of the regulatory sequence of the core promoter and second enhancer of human hepatitis B virus (HBV). Through this binding, NREBP represses HBV core promoter activity, transcription of HBV genes and production of HBV virions. NREBP has sequence similarities with other DNA-binding structural proteins such as gallin, Mos and oncoproteins of the Myc family. NREBP may be involved in protecting cells from apoptosis and in pre-mRNA splicing. Ten isoforms exist due to alternative splicing events. |