Genomic binding by the Drosophila Myc, Max, Mad/Mnt transcription factor network.
The Myc/Max/Mad transcription factor network is critically involved in cell behavior; however, there is relatively little information on its genomic binding sites. We have employed the DamID method to carry out global genomic mapping of the Drosophila Myc, Max, and Mad/Mnt proteins. Each protein was tethered to Escherichia coli DNA adenine-methyltransferase (Dam) permitting methylation proximal to in vivo binding sites in Kc cells. Microarray analyses of methylated DNA fragments reveals binding to multiple loci on all major Drosophila chromosomes. This approach also reveals dynamic interactions among network members as we find that increased levels of dMax influence the extent of dMyc, but not dMnt, binding. Computer analysis using the REDUCE algorithm demonstrates that binding regions correlate with the presence of E-boxes, CG repeats, and other sequence motifs. The surprisingly large number of directly bound loci ( approximately 15% of coding regions) suggests that the network interacts widely with the genome. Furthermore, we employ microarray expression analysis to demonstrate that hundreds of DamID-binding loci correspond to genes whose expression is directly regulated by dMyc in larvae. These results suggest that a fundamental aspect of Max network function involves widespread binding and regulation of gene expression.
Orian
Amir
A
Division of Basic Sciences and Divison of Human Biology, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA.
van Steensel
Bas
B
Delrow
Jeffrey
J
Bussemaker
Harmen J
HJ
Li
Ling
L
Sawado
Tomoyuki
T
Williams
Eleanor
E
Loo
Lenora W M
LW
Cowley
Shaun M
SM
Yost
Cynthia
C
Pierce
Sarah
S
Edgar
Bruce A
BA
Parkhurst
Susan M
SM
Eisenman
Robert N
RN
D000818:Animals; D050976:Basic-Leucine Zipper Transcription Factors; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D016153:Genes, Suppressor; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C112506:MAD protein, Drosophila; C067850:Myc associated factor X; D009687:Nuclear Proteins; D016271:Proto-Oncogene Proteins c-myc; D014157:Transcription Factors; D004247:DNA