Insulators are conserved genomic elements that organize chromosomes into independent functional domains to maintain transcriptional fidelity. These elements protect gene expression from positive and negative regulatory effects by blocking interactions between enhancers, silencers, and promoters. The goal of our studies is to understand molecular mechanisms used by insulators to organize eukaryotic genomes into transcriptional domains. In studies described herein, the Drosophila gypsy insulator will be used as model to elucidate mechanisms of insulator action. The gypsy insulator is a well-studied insulator that was isolated from the gypsy retrovirus. This insulator is the only one known that requires a single DNA binding protein, the Suppressor of Hairy-wing [Su(Hw)]. Once bound to chromosomes, the Su(Hw) protein recruits the BTB/POZ domain protein, Modifier67.2, to generate a protein complex that establishes insulator activity. Mutations in the genes encoding the gypsy insulator proteins are available, making the system amenable to genetic manipulation. The gypsy insulator proteins associate with hundreds of genomic sites that are not sites of gypsy retroviral insertion. These observation suggest that Su(Hw) and Modifier67.2 have global roles in establishing independent regulatory domains in the Drosophila genome. We will test this hypothesis by determining the DNA and proteins requirements of endogenous Su(Hw) sites and define their role in organization of regulatory domains throughout chromosomes. These data will provide insights into mechanisms used to delimit transcriptional regulatory domains within eukaryotic genomes, thereby providing insights into fundamental questions of control of enhancer and silencer function. Understanding mechanisms of insulators action has therapeutic utility for gene therapy, as inclusion of insulators within gene transfer vectors can improve the expression of transgenes, while preventing inappropriate regulatory effects of gene transfer vectors on endogenous gene expression.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
2R01GM042539-14A1
Application #
6873091
Study Section
Genetics Study Section (GEN)
Program Officer
Carter, Anthony D
Project Start
1991-04-01
Project End
2008-11-30
Budget Start
2004-12-03
Budget End
2005-11-30
Support Year
14
Fiscal Year
2005
Total Cost
$369,936
Indirect Cost
Name
University of Iowa
Department
Biochemistry
Type
Schools of Medicine
DUNS #
062761671
City
Iowa City
State
IA
Country
United States
Zip Code
52242
Duan, Tingting; Geyer, Pamela K (2018) Spermiogenesis and Male Fertility Require the Function of Suppressor of Hairy-Wing in Somatic Cyst Cells of Drosophila. Genetics 209:757-772
Baxley, Ryan M; Bullard, James D; Klein, Michael W et al. (2017) Deciphering the DNA code for the function of the Drosophila polydactyl zinc finger protein Suppressor of Hairy-wing. Nucleic Acids Res 45:4463-4478
Soshnev, Alexey A; Baxley, Ryan M; Manak, J Robert et al. (2013) The insulator protein Suppressor of Hairy-wing is an essential transcriptional repressor in the Drosophila ovary. Development 140:3613-23
Hohl, Amber M; Thompson, Morgan; Soshnev, Alexey A et al. (2012) Restoration of topoisomerase 2 function by complementation of defective monomers in Drosophila. Genetics 192:843-56
Soshnev, Alexey A; He, Bing; Baxley, Ryan M et al. (2012) Genome-wide studies of the multi-zinc finger Drosophila Suppressor of Hairy-wing protein in the ovary. Nucleic Acids Res 40:5415-31
Soshnev, Alexey A; Ishimoto, Hiroshi; McAllister, Bryant F et al. (2011) A conserved long noncoding RNA affects sleep behavior in Drosophila. Genetics 189:455-68
Geyer, Pamela K; Vitalini, Michael W; Wallrath, Lori L (2011) Nuclear organization: taking a position on gene expression. Curr Opin Cell Biol 23:354-9
Baxley, Ryan M; Soshnev, Alexey A; Koryakov, Dmitry E et al. (2011) The role of the Suppressor of Hairy-wing insulator protein in Drosophila oogenesis. Dev Biol 356:398-410
Kuhn-Parnell, Emily J; Helou, Cecilia; Marion, David J et al. (2008) Investigation of the properties of non-gypsy suppressor of hairy-wing-binding sites. Genetics 179:1263-73
Soshnev, Alexey A; Li, Xingguo; Wehling, Misty D et al. (2008) Context differences reveal insulator and activator functions of a Su(Hw) binding region. PLoS Genet 4:e1000159

Showing the most recent 10 out of 15 publications