SDC-3 coordinates the assembly of a dosage compensation complex on the nematode X chromosome.
X chromosome expression in C. elegans is controlled by a chromosome-wide regulatory process called dosage compensation that specifically reduces by half the level of transcripts made from each hermaphrodite X chromosome. This process equalizes X expression between the sexes (XX hermaphrodites and XO males), despite their two-fold difference in X chromosome dose, and thereby prevents sex-specific lethality. Dosage compensation is achieved by a protein complex that associates with X in a sex-specific fashion to modulate gene expression. SDC-3, a protein that coordinately controls both sex determination and dosage compensation, activates dosage compensation by directing the dosage compensation protein complex to the hermaphrodite X chromosomes. We show that SDC-3 coordinates this assembly through its own sex-specific association with X. SDC-3 in turn requires other members of the dosage compensation gene hierarchy for its stability and its X localization. In addition, SDC-3 requires its own zinc finger motifs and an amino-terminal region for its X association. Our experiments suggest the possible involvement of zinc finger motifs in X chromosome recognition and the amino-terminal region in interactions with other dosage compensation proteins.
Davis
T L
TL
Department of Molecular and Cell Biology, University of California, Berkeley 94720-3204, USA.
Meyer
B J
BJ
D000818:Animals; D017173:Caenorhabditis elegans / Q000235:genetics*; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D012734:Disorders of Sex Development; D004303:Dosage Compensation, Genetic; D005260:Female; D015801:Helminth Proteins / Q000378:metabolism / Q000502:physiology*; D006579:Heterozygote; D008297:Male; D008958:Models, Molecular; D016296:Mutagenesis; D012733:Sex Differentiation; D014960:X Chromosome / Q000378:metabolism; D016335:Zinc Fingers
D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; D015801:Helminth Proteins; C079666:Sdc-3 protein, C elegans