The E2A gene product contains two separable and functionally distinct transcription activation domains.
The E2A gene encodes transcription factors of the helix-loop-helix (HLH) family which are implicated in cell-specific transcriptional control in several cell lineages, including pancreatic beta cells. In the present work, we show by deletion mapping of both the E2A protein itself and the Gal4-E2A fusion protein that the protein contains at least two distinct activation domains. One domain (located between amino acids 1 and 153) functions efficiently in a variety of mammalian cell lines. The second domain (located between amino acids 369 and 485) functions preferentially in pancreatic beta cell lines. The latter domain shows a pattern of heptad repeats of leucine residues characteristics of "leucine zipper" transcription factors; site-directed mutagenesis of leucines within this repeat led to substantial reductions in activity. The selective properties of this activation domain may contribute to cell-specific transcription directed by the E2A gene.
Aronheim
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A
Biochemistry Department, Weizmann Institute of Science, Rehovot, Israel.
Shiran
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R
Rosen
A
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Walker
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MD
D000256:Adenoviridae / Q000235:genetics / Q000378:metabolism*; D017502:Adenovirus E2 Proteins / Q000235:genetics / Q000378:metabolism*; D000260:Adenoviruses, Human / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D004277:DNA, Single-Stranded / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D005814:Genes, Viral; D006367:HeLa Cells; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009838:Oligodeoxyribonucleotides; D051381:Rats; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
D017502:Adenovirus E2 Proteins; D004277:DNA, Single-Stranded; D009838:Oligodeoxyribonucleotides; D015534:Trans-Activators