Cell-cell communication plays an important role in the development of many tissues. This research project investigates the mechanisms that activate the Drosophila Epidermal Growth Factor receptor (Egfr) during oogenesis, and the cellular pathways that mediate the response to this receptor tyrosine kinase in the ovarian follicle cells. We have shown that the Drosophila Egfr is expressed in the follicle cells and receives a highly controlled signal from the germline encoded by the gene gurken (grk). Restricted activation of the Egfr by Grk initiates several different follicle cell responses and is required for axis formaton of the egg and embryo. We have also shown that grk expression in oogenesis is regulated by developmental inputs as well as a meiotic checkpoint. Our goal is to study the molecular regulation of Grk production in the germline and to analyze the patterning and differentiation processes that are activated in the follicle cells in response to receptor activation.
Our specific aims are: 1) The regulation of grk translation: We will identify proteins that bind to the grk RNA and regulate its translation using CRISPR technology. We will determine how the meiotic checkpoint regulates translation of grk and focus on the interaction of Vasa protein with the translation initiation factor eIF1A in the checkpoint activated germline. We will perform ribosome footprinting assays on the grk RNA which will allow us to determine the direct effects on ribosome binding by the developmental regulatory factors and by the meiotic checkpoint. 2) Analysis of the follicle cell response to EGFR activation. We will analyze the cooperation of the Egfr pathway with the Notch and JAK/STAT pathway during posterior follicle cell differentiation. We have isolated mutations that uncover interactions of Egfr signaling with the Notch pathway and will investigate these interactions at a molecular level. One focus is the transcriptional regulator Hamlet that acts downstream of Notch in neuronal cells. Transcriptional profiling and ChIP-Seq experiments will provide a global analysis of the cooperation between the signaling pathways. We will also analyze the cell biological response to Egfr signaling in the posterior follicle cells with a focus on the production of the posterior polarizing signal and its dependence on the actin cytoskeleton and microvilli. Mutations in checkpoint genes, as well as unregulated activation of the human Egfr have been implicated in several forms of cancer. Our work will elucidate the regulatory mechanisms that control the activity of this receptor in an in vivo situation. It will also analyze the interactions between Egfr and other signaling pathways and provide a molecular understanding of the downstream effector pathways operating in the follicle cell epithelium, a model system for epithelial development and differentiation.

Public Health Relevance

This project investigates the regulation and cellular effects of the Drosophila Epidermal Growth Factor receptor. In humans, this type of receptor is frequently mutated in cancer, in particular in breast and lung cancer, and novel drugs that specifically target the receptor and its downstream pathway have already shown significant gains in the fight against cancer. Our work identifies further genes that act in the same pathway as the receptor and these genes will provide new targets for specific cancer drugs, as well as allowing us to describe the pathways by which the activity and the effects of this important receptor are kept under control by normal cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM077620-11
Application #
9204840
Study Section
Development - 1 Study Section (DEV1)
Program Officer
Gibbs, Kenneth D
Project Start
2007-02-01
Project End
2019-01-31
Budget Start
2017-02-01
Budget End
2018-01-31
Support Year
11
Fiscal Year
2017
Total Cost
$330,519
Indirect Cost
$123,519
Name
Princeton University
Department
Biochemistry
Type
Schools of Arts and Sciences
DUNS #
002484665
City
Princeton
State
NJ
Country
United States
Zip Code
08543
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Johnson, Heath E; Goyal, Yogesh; Pannucci, Nicole L et al. (2017) The Spatiotemporal Limits of Developmental Erk Signaling. Dev Cell 40:185-192
Pritykin, Yuri; Brito, Tarcisio; Schupbach, Trudi et al. (2017) Integrative analysis unveils new functions for the Drosophila Cutoff protein in noncoding RNA biogenesis and gene regulation. RNA 23:1097-1109
Devergne, Olivier; Sun, Gina H; Schüpbach, Trudi (2017) Stratum, a Homolog of the Human GEF Mss4, Partnered with Rab8, Controls the Basal Restriction of Basement Membrane Proteins in Epithelial Cells. Cell Rep 18:1831-1839
Jindal, Granton A; Goyal, Yogesh; Yamaya, Kei et al. (2017) In vivo severity ranking of Ras pathway mutations associated with developmental disorders. Proc Natl Acad Sci U S A 114:510-515
Schupbach, Trudi (2016) The Complexities and Unexpected Insights of Developmental Genetic Analysis. Curr Top Dev Biol 117:319-30
Lim, Bomyi; Dsilva, Carmeline J; Levario, Thomas J et al. (2015) Dynamics of Inductive ERK Signaling in the Drosophila Embryo. Curr Biol 25:1784-90
Devergne, Olivier; Tsung, Karen; Barcelo, Gail et al. (2014) Polarized deposition of basement membrane proteins depends on Phosphatidylinositol synthase and the levels of Phosphatidylinositol 4,5-bisphosphate. Proc Natl Acad Sci U S A 111:7689-94
Li, Wei; Klovstad, Martha; Schüpbach, Trudi (2014) Repression of Gurken translation by a meiotic checkpoint in Drosophila oogenesis is suppressed by a reduction in the dose of eIF1A. Development 141:3910-21
Domanitskaya, Elena; Anllo, Lauren; Schüpbach, Trudi (2014) Phantom, a cytochrome P450 enzyme essential for ecdysone biosynthesis, plays a critical role in the control of border cell migration in Drosophila. Dev Biol 386:408-18

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