The characterization of the ABF-1 promoter

• Main Author: Ezpeleta, Jessica
• Format: Others
• Published: Scholarly Commons 2001
• Subjects: Promoters (Genetics); Genetic transcription; Life Sciences
• Online Access: https://scholarlycommons.pacific.edu/uop_etds/559; https://scholarlycommons.pacific.edu/cgi/viewcontent.cgi?article=1558&context=uop_etds

The basic helix-loop-helix (bHLH) family oftranscription factors consists of proteins involved in cellular proliferation and differentiation. The HLH structure plays a key role in protein-protein dimerization and with the DNA target sites, referred to as E boxes containing the consensus DNA sequence CANNTG. One class of mammalian class I bHLH proteins includes products of the E2A gene, which result from alternative splicing (E12, E47, and ITF), E2-2 and HEB. E2A proteins have also been detected in most cell lines with high levels of expression in lymphoid- and pancreatic cells. It has also been demonstrated that E2A is required for B cell maturation, T cell development and has been shown to function as tumor suppressors. To date, an E2A-interacting bHLH transcription factor largely restricted to activated B lymphocytes, called ABF -1, was isolated using the two-hybrid system. ABF -1 is the only B cell restricted bHLH protein isolated. ABF-1/E2A heterodimers have been detected in B lymphocytes. In these studies, the mapping of the ABF-1 promoter and the critical 5' regulatory elements that control ABF-1 gene expression were analyzed through 5' deletional analysis. 5' -DNA flanking pieces of the promoter region were created through PCR and inserted into a promoterless cloning vector containing the firefly luciferase reporter gene. RT -PCR analysis and anchored PCR was utilized to demonstrate the transcriptional activity of the - promoter region of the ABF-1 gene. Transient transfections were completed to determine critical regulatory sequences. The promoter location was confirmed through computer analysis of the nucleotide sequence and deletional analysis.