The role of E2A proteins in pancreatic beta cells and the characterization of an anti-E2A specific polyclonal antiserum

• Main Author: Pongo, Elizabeth C.
• Format: Others
• Published: Scholarly Commons 1997
• Subjects: Pancreas; Proteins; Genes; Life Sciences
• Online Access: https://scholarlycommons.pacific.edu/uop_etds/2303; https://scholarlycommons.pacific.edu/cgi/viewcontent.cgi?article=3302&context=uop_etds

Basic helix-loop-helix (bHLH) proteins belong to a class of transcription factors that are critical regulators of development, cell growth and differentiation. One particular family member includes the products of the E2A gene, E12 (Pan-2) and E47 (Pan-1), ubiquitous transcription factors localized in the nucleus. E12 and E47 gene products are generated by alternative RNA splicing. E12 and E47 proteins have been implicated as transcriptional regulators of the rat I insulin gene, immunoglobulin light and heavy chain genes and several muscle-specific genes. To delineate the role ofE2A proteins in directing insulin gene transcription, we have characterized an anti-E2A polyclonal antiserum which recognizes both E12 and E47 and used this reagent to study E2A proteins in the pancreas. In these studies, we have demonstrated that the anti-E2A polyclonal antiserum is highly specific for E2A proteins in a variety of different cell lines representing different tissues. Furthermore, using this immunohistochemical tool, we have demonstrated that E2A proteins are posttranslationally modified in beta cells, insulin producing cells in the pancreas. We also provide evidence that a posttranslationally modified form of E2A protein is involved in glucose-induced insulin gene transcription in beta cells. Lastly, we provide evidence that E2A proteins are associated with other bHLH proteins or other non-bHLH proteins in pancreatic beta cells.