Dosage compensation refers to the equalization of most X-linked gene products between males, which have one X chromosome and a single dose of X-linked genes, and females, which have two X's and two doses of such genes. In D. melanogaster, this equalization is achieved by assembling a multi-protein complex on the X chromosome in male somatic cells; the function of this complex is to enhance the transcription of X-linked genes in males. Complexes with a generally similar function have been identified in organisms as evolutionarily distant as yeast and humans; all appear to perform their function by remodeling chromatin. Therefore, the complete molecular definition of the mechanism used by flies to achieve X-chromosome dosage compensation will provide fundamental insights into the role that chromatin remodeling plays in the regulation of gene activity. Over the years, we have laid the necessary groundwork to understand the underlying regulatory mechanism of dosage compensation, at the molecular level and it is particularly satisfying to see that our hopes for this model system are being realized. Over the next grant period we propose the following specific experimental aims. (1) We will identify the remain components of the complex. To achieve this specific aim, we will supplement the genetic approaches that have relied on identifying gene products on the basis of sex-specific lethality with biochemical methods. (2) We will identify the sequence features that distinguish the X chromosome from the remainder of the genome. To date efforts, by others and ourselves have failed to reveal the features, which confer binding specificity to the dosage compensation complex. We will use a variety of molecular genetic and biochemical approaches to address this important aspect of the regulatory mechanism. (3) We will determine the nature of the mechanism underlying the function of the complex. This will involve a study of the interaction of the different components among themselves as well as with chromatin.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM015691-32A1
Application #
6046043
Study Section
Genetics Study Section (GEN)
Program Officer
Greenberg, Judith H
Project Start
1974-09-01
Project End
2003-12-31
Budget Start
2000-01-01
Budget End
2000-12-31
Support Year
32
Fiscal Year
2000
Total Cost
$325,495
Indirect Cost
Name
Emory University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
042250712
City
Atlanta
State
GA
Country
United States
Zip Code
30322
Cugusi, Simona; Li, Yujing; Jin, Peng et al. (2016) The Drosophila Helicase MLE Targets Hairpin Structures in Genomic Transcripts. PLoS Genet 12:e1005761
Cugusi, Simona; Kallappagoudar, Satish; Ling, Huiping et al. (2015) The Drosophila Helicase Maleless (MLE) is Implicated in Functions Distinct From its Role in Dosage Compensation. Mol Cell Proteomics 14:1478-88
Cugusi, Simona; Ramos, Edward; Ling, Huiping et al. (2013) Topoisomerase II plays a role in dosage compensation in Drosophila. Transcription 4:238-50
Kallappagoudar, Satish; Dammer, Eric B; Duong, Duc Minh et al. (2013) Expression, purification and proteomic analysis of recombinant histone H4 acetylated at lysine 16. Proteomics 13:1687-91
Dunlap, David; Yokoyama, Ruth; Ling, Huiping et al. (2012) Distinct contributions of MSL complex subunits to the transcriptional enhancement responsible for dosage compensation in Drosophila. Nucleic Acids Res 40:11281-91
Morra, Rosa; Yokoyama, Ruth; Ling, Huiping et al. (2011) Role of the ATPase/helicase maleless (MLE) in the assembly, targeting, spreading and function of the male-specific lethal (MSL) complex of Drosophila. Epigenetics Chromatin 4:6
Lucchesi, John C (2009) The structure-function link of compensated chromatin in Drosophila. Curr Opin Genet Dev 19:550-6