Functional dissection of Drosophila abdominal-B protein.
The Abdominal-B gene is unique among homeotic Drosophila genes as it encodes two proteins m and r which confer different functions. The m protein corresponds to an r protein with a large N-terminal extension; the two proteins contain the same homeodomain. We have used a transient co-transfection assay, based on HeLa cells, to analyse the intrinsic function of m and r protein in activating transcription. We find two strong transcriptional activation domains in the common part of the two proteins. The m-specific exon contains additional transcriptional activation potential. Despite this, the m protein is a weaker transcriptional activator than the r protein. Apparently, there are inhibitory sequences in the m-specific exon which, in the embryo, may have a role in masking r function in the intact m protein.
Zoological Institute, University of Zürich, Switzerland.
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Bienz
D000818:Animals; D004330:Drosophila / Q000235:genetics / Q000502:physiology*; D029721:Drosophila Proteins; D005091:Exons; D005786:Gene Expression Regulation / Q000235:genetics / Q000502:physiology; D005801:Genes, Homeobox / Q000235:genetics / Q000502:physiology*; D018398:Homeodomain Proteins; D007301:Insect Hormones / Q000235:genetics / Q000502:physiology*; D014158:Transcription, Genetic / Q000235:genetics
C062393:Abd-B proteins, Drosophila; D029721:Drosophila Proteins; D018398:Homeodomain Proteins; D007301:Insect Hormones