Cumulative contributions of weak DNA determinants to targeting the Drosophila dosage compensation complex.
Fine-tuning of X chromosomal gene expression in Drosophila melanogaster involves the selective interaction of the Dosage Compensation Complex (DCC) with the male X chromosome, in order to increase the transcription of many genes. However, the X chromosomal DNA sequences determining DCC binding remain elusive. By adapting a 'one-hybrid' assay, we identified minimal DNA elements that direct the interaction of the key DCC subunit, MSL2, in cells. Strikingly, several such novel MSL2 recruitment modules have very different DNA sequences. The assay revealed a novel, 40 bp DNA element that is necessary for recruitment of DCC to an autosomal binding site in flies in the context of a longer sequence and sufficient by itself to direct recruitment if trimerized. Accordingly, recruitment of MSL2 to the single 40 bp element in cells was weak, but as a trimer approached the power of the strongest DCC recruitment site known to date, the roX1 DH site. This element is the shortest MSL2 recruitment sequence known to date. The results support a model for MSL2 recruitment according to which several different, degenerate sequence motifs of variable affinity cluster and synergise to form a high affinity site.
Gilfillan
Gregor D
GD
Adolf-Butenandt Institut, Molekularbiologie, Ludwig Maximilian Universität, Schillerstrasse 44, 80336 Munich, Germany.
König
Cornelia
C
Dahlsveen
Ina K
IK
Prakoura
Nicky
N
Straub
Tobias
T
Lamm
Rosemarie
R
Fauth
Torsten
T
Becker
Peter B
PB
D000818:Animals; D001665:Binding Sites; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I; D004303:Dosage Compensation, Genetic; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics*; D005260:Female; D008297:Male; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding; D012333:RNA, Messenger / Q000032:analysis; D014157:Transcription Factors / Q000378:metabolism*; D014162:Transfection; D020798:Two-Hybrid System Techniques; D014960:X Chromosome / Q000737:chemistry* / Q000378:metabolism
D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; C094166:msl-2 protein, Drosophila; D004247:DNA; D003850:Deoxyribonuclease I