Targeting of MOF, a putative histone acetyl transferase, to the X chromosome of Drosophila melanogaster.
Dosage compensation ensures that males with a single X chromosome have the same amount of most X-linked gene products as females with two X chromosomes. In Drosophila, this equalization is achieved by a twofold enhancement of the level of transcription of the X in males relative to each X chromosome in females. The products of at least five genes, maleless (mle), male-specific lethal 1, 2, and 3 (msl-1, msl-2, msl-3) and males absent on the first (mof), are necessary for dosage compensation. The proteins produced by these genes form a complex that is preferentially associated with numerous sites on the X chromosome in somatic cells of males but not of females. Binding of the dosage compensation complex to the X chromosome is correlated with a significant increase in the presence of a specific histone isoform, histone 4 acetylated at lysine 16, on this chromosome. Experimental results and sequence analysis suggest that the mof gene encodes an acetyl transferase that plays a direct role in the specific histone acetylation associated with dosage compensation. Recently, RNA transcripts encoded by at least two different genes have also been found associated with the X chromosome in males. We have studied the role played by the various components of the complex in the targeting of MOF to the X chromosome. To this end, we have used indirect cytoimmunofluorescence to monitor the binding of these components in males carrying complete or partial loss-of-function mutations as well as in XX individuals in which formation of the dosage compensation complex has been induced by genetic means.
Gu
W
W
Department of Biology, Emory University, Atlanta, Georgia 30322, USA.
Szauter
P
P
Lucchesi
J C
JC
D000123:Acetyltransferases / Q000235:genetics*; D000818:Animals; D002868:Chromosomal Proteins, Non-Histone; D002874:Chromosome Mapping; D004265:DNA Helicases; D004268:DNA-Binding Proteins; D004303:Dosage Compensation, Genetic; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000201:enzymology / Q000235:genetics*; D017344:Genes, Insect; D051548:Histone Acetyltransferases; D008297:Male; D009687:Nuclear Proteins; D012316:RNA Nucleotidyltransferases / Q000235:genetics; D014157:Transcription Factors / Q000235:genetics; D014960:X Chromosome
D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D014157:Transcription Factors; C070837:mle protein, Drosophila; D000123:Acetyltransferases; D051548:Histone Acetyltransferases; C111063:mof protein, Drosophila; D012316:RNA Nucleotidyltransferases; D004265:DNA Helicases