Project description:Drosophila eye specification an development relies on a collection of transcription factors termed the retinal determination gene network (RDGN). Two members of this network, Eyes absent (EYA) and Sine oculis (SO), form a transcriptional complex in which EYA provides the transactivation function while SO provides the DNA binding activity. EYA also function as a protein tyrosine phosphatase, raising the question of whether transcriptional output is dependent or independent of phosphatase activity. To explore this, we used microarrays together with binding site analysis, quantitative real-time PCR, chromatin immunoprecipitation, genetics, and in vivo expression analysis to identify new EYA-SO targets. In parallel, we examined the expression profiles of tissue expressing phosphatase mutant eya and found that reducing phosphatase activity did not globally impair transcriptional output. Among the targets identified by our analysis was the cell cycle regulatory gene, string (stg), suggesting that EYA and SO may influence cell proliferation through transcriptional regulation of stg. Future investigation into the regulation of stg and other EYA-SO targets identified in this study will help elucidate the transcriptional circuitries whereby output from the RDGN integrates with other signaling inputs to coordinate retinal development. Experiment Overall Design: We compared gene expression across duplicate samples for controls in which eya was not overexpressed to duplicate samples in which a wildtye overexpressed eya transgene, an eya mutant transgene with the D493N mutation, which reduces phosphatase activity, and a second eya mutant transgene with the E728Q mutation, which has little is any posphatase activity.
Project description:Drosophila eye specification an development relies on a collection of transcription factors termed the retinal determination gene network (RDGN). Two members of this network, Eyes absent (EYA) and Sine oculis (SO), form a transcriptional complex in which EYA provides the transactivation function while SO provides the DNA binding activity. EYA also function as a protein tyrosine phosphatase, raising the question of whether transcriptional output is dependent or independent of phosphatase activity. To explore this, we used microarrays together with binding site analysis, quantitative real-time PCR, chromatin immunoprecipitation, genetics, and in vivo expression analysis to identify new EYA-SO targets. In parallel, we examined the expression profiles of tissue expressing phosphatase mutant eya and found that reducing phosphatase activity did not globally impair transcriptional output. Among the targets identified by our analysis was the cell cycle regulatory gene, string (stg), suggesting that EYA and SO may influence cell proliferation through transcriptional regulation of stg. Future investigation into the regulation of stg and other EYA-SO targets identified in this study will help elucidate the transcriptional circuitries whereby output from the RDGN integrates with other signaling inputs to coordinate retinal development. Keywords: gain of function, expression comparison
Project description:Medulloblastoma is one of the most common malignant brain tumors of children, and 30% of medulloblastomas are driven by gain-of-function genetic lesions in the Sonic hedgehog (SHH) signaling pathway. Eyes Absent (EYA1), a haloacid dehalogenase (HAD) phosphatase and co-transcription factor, is critical for tumorigenesis and proliferation of SHH-medulloblastoma (SHH-MB). Benzarone and benzbromarone have been identified as allosteric inhibitors for the Eya proteins. Using benzarone as a point of departure, we developed a panel of 35 derivatives, and identified one new compound, DS-1-38, that functions as an Eya-antagonist, opposes SHH-signaling, inhibits SHH-MB growth in vitro and in vivo, shows excellent brain penetrance and increases the lifespan of mice predisposed to fatal SHH-MB. Our data suggest that DS-1-38 provides a path for developing targeted therapeutic for pediatric SHH-MB.
Project description:Medulloblastoma is one of the most common malignant brain tumors of children, and 30% of medulloblastomas are driven by gain-of-function genetic lesions in the Sonic hedgehog (SHH) signaling pathway. Eyes Absent (EYA1), a haloacid dehalogenase (HAD) phosphatase and co-transcription factor, is critical for tumorigenesis and proliferation of SHH-medulloblastoma (SHH-MB). Benzarone and benzbromarone have been identified as allosteric inhibitors for the Eya proteins. Using benzarone as a point of departure, we developed a panel of 35 derivatives, and identified one new compound, DS-1-38, that functions as an Eya-antagonist, opposes SHH-signaling, inhibits SHH-MB growth in vitro and in vivo, shows excellent brain penetrance and increases the lifespan of mice predisposed to fatal SHH-MB. Our data suggest that DS-1-38 provides a path for developing targeted therapeutic for pediatric SHH-MB.
Project description:This SuperSeries is composed of the following subset Series: GSE3286: Drosophila Life Cycle GSE3287: Unfertilized eggs GSE3288: Eyes absent mutant adults Abstract: Molecular genetic studies of Drosophila melanogaster have led to profound advances in understanding the regulation of development. Here we report gene expression patterns for nearly one-third of all Drosophila genes during a complete time course of development. Mutations that eliminate eye or germline tissue were used to further analyze tissue-specific gene expression programs. These studies define major characteristics of the transcriptional programs that underlie the life cycle, compare development in males and females, and show that large-scale gene expression data collected from whole animals can be used to identify genes expressed in particular tissues and organs or genes involved in specific biological and biochemical processes. Refer to individual Series