Functional analysis of murine CBF1 during Drosophila development.
Transcription factors of the CSL family are the main mediators of the Notch signalling pathway. The CSL factor in Drosophila is called Suppressor of Hairless (Su(H)) and it has been shown that it acts as a transcriptional repressor in the absence of a Notch signal and as a transcriptional activator in its presence in several developmental contexts. Furthermore, recent data suggest that Su(H) can also activate and maintain transcription of some target genes in a Notch-independent manner. However, although it has been shown that the mammalian CSL ortholog, CBF1, acts as a repressor of transcription in cell culture experiments, so far in vivo evidence for such a function has been lacking. Moreover, it is not known whether CBF1 can activate transcription in a Notch-independent manner, just like Su(H). Here we have investigated these questions by introducing murine CBF1 (mCBF1) and asked whether it can functionally replace Su(H) during Drosophila development. We found that this is indeed the case. We show that mCBF1 can act as a repressor of transcription and can activate and maintain the expression of some target genes in a Notch-independent manner. Our results, therefore, indicate that CBF1 can exert these functions also in its normal context, that is during mammalian development.
Kaspar
Markus
M
Institute of Genetics, University of Cologne, Zuelpicherstrasse 47, 50674 Cologne, Germany.
Klein
Thomas
T
D000595:Amino Acid Sequence; D000818:Animals; D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors / Q000502:physiology*; D004330:Drosophila / Q000235:genetics / Q000254:growth & development*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D006651:Histocytochemistry; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism*; D008969:Molecular Sequence Data; D051880:Receptors, Notch / Q000235:genetics / Q000378:metabolism; D012097:Repressor Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014157:Transcription Factors; D015533:Transcriptional Activation; D014921:Wings, Animal / Q000254:growth & development
D051778:Basic Helix-Loop-Helix Leucine Zipper Transcription Factors; D029721:Drosophila Proteins; D051819:Immunoglobulin J Recombination Signal Sequence-Binding Protein; D019476:Insect Proteins; C497571:Rbpj protein, mouse; D051880:Receptors, Notch; D012097:Repressor Proteins; C088731:Su(H) protein, Drosophila; D014157:Transcription Factors