title: Bonus, a Drosophila TIF1 homolog, is a chromatin-associated protein that acts as a modifier of position-effect variegation.
abstract: Bonus, a Drosophila TIF1 homolog, is a nuclear receptor cofactor required for viability, molting, and numerous morphological events. Here we establish a role for Bonus in the modulation of chromatin structure. We show that weak loss-of-function alleles of bonus have a more deleterious effect on males than on females. This male-enhanced lethality is not due to a defect in dosage compensation or somatic sex differentiation, but to the presence of the Y chromosome. Additionally, we show that bonus acts as both an enhancer and a suppressor of position-effect variegation. By immunostaining, we demonstrate that Bonus is associated with both interphase and prophase chromosomes and through chromatin immunoprecipitation show that two of these sites correspond to the histone gene cluster and the Stellate locus.
authors.affiliation: Department of Molecular and Human Genetics, Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: R B
authors.initials: RB
authors.lastname: Beckstead
authors.forename: S S
authors.initials: SS
authors.lastname: Ner
authors.forename: K G
authors.initials: KG
authors.lastname: Hales
authors.forename: T A
authors.initials: TA
authors.lastname: Grigliatti
authors.forename: B S
authors.initials: BS
authors.lastname: Baker
authors.forename: H J
authors.initials: HJ
authors.lastname: Bellen
mesh_terms: D000818:Animals; D002843:Chromatin / Q000235:genetics* / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D004330:Drosophila / Q000235:genetics* / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004742:Enhancer Elements, Genetic; D005260:Female; D005786:Gene Expression Regulation; D017344:Genes, Insect; D007150:Immunohistochemistry; D008297:Male; D018613:Microscopy, Confocal; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D014998:Y Chromosome
chemical_list: C502013:Bon protein, Drosophila; D002843:Chromatin; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D012097:Repressor Proteins; D014157:Transcription Factors; C093517:transcriptional intermediary factor 1