title: Ken & barbie selectively regulates the expression of a subset of Jak/STAT pathway target genes.
abstract: A limited number of evolutionarily conserved signal transduction pathways are repeatedly reused during development to regulate a wide range of processes. Here we describe a new negative regulator of JAK/STAT signaling and identify a potential mechanism by which the pleiotropy of responses resulting from pathway activation is generated in vivo. As part of a genetic interaction screen, we have identified Ken & Barbie (Ken) , which is an ortholog of the mammalian proto-oncogene BCL6 , as a negative regulator of the JAK/STAT pathway. Ken genetically interacts with the pathway in vivo and recognizes a DNA consensus sequence overlapping that of STAT92E in vitro. Tissue culture-based assays demonstrate the existence of Ken-sensitive and Ken-insensitive STAT92E binding sites, while ectopically expressed Ken is sufficient to downregulate a subset of JAK/STAT pathway target genes in vivo. Finally, we show that endogenous Ken specifically represses JAK/STAT-dependent expression of ventral veins lacking (vvl) in the posterior spiracles. Ken therefore represents a novel regulator of JAK/STAT signaling whose dynamic spatial and temporal expression is capable of selectively modulating the transcriptional repertoire elicited by activated STAT92E in vivo.
authors.affiliation: Department of Molecular Developmental Biology, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany.
authors.forename: Natalia I
authors.initials: NI
authors.lastname: Arbouzova
authors.forename: Erika A
authors.initials: EA
authors.lastname: Bach
authors.forename: Martin P
authors.initials: MP
authors.lastname: Zeidler
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D017930:Genes, Reporter; D053612:Janus Kinases; D050809:POU Domain Factors / Q000378:metabolism; D010802:Phylogeny; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D050791:STAT Transcription Factors / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C508384:Ken protein, Drosophila; D050809:POU Domain Factors; D050791:STAT Transcription Factors; C105675:Stat92E protein, Drosophila; D014157:Transcription Factors; C091575:vvl protein, Drosophila; D011505:Protein-Tyrosine Kinases; D053612:Janus Kinases; C085845:hop protein, Drosophila