Cell migration is a fascinating feature of embryonic development, and improperly regulated cell migration contributes to birth defects and tumor metastasis. We have developed a simple model system for a forward genetic approach to the study of cell motility in vivo, the migration of a subset of follicle cells, known as border cells, in the Drosophila ovary. We have established that multiple extracellular signals regulate their movement. 1) a global steroid hormone signal, ecdysone, acting through the ecdysone receptor and a transcriptional coactivator called Taiman; 2) a highly localized cytokine signal, which activates the JAK/STAT pathway; and 3) several growth factors, which signal through the EGFR and PVR receptor tyrosine kinases to guide the cells to their destination. In addition we have studied a variety of cytoskeleton-associated proteins and cell adhesion molecules that function in border cell migration. This proposal explores the mechanisms by which cell adhesion is dynamically regulated in migrating border cells, an important aspect of cell motility that is not well understood for any cell type. We propose three specific aims. The first is to investigate the mechanisms that govern trafficking and stability of E-cadherin, a homophilic cell-cell adhesion molecule that is required in border cells and in the cells upon which they migrate. To test whether E-cadherin is turned over more rapidly in border cells than in non-migrating follicle cells, we will employ a previously characterized variant of the red fluorescent protein that changes color over time, fused to E-cadherin. We will investigate whether EGFR and PVR signaling destabilizes cell adhesion by phosphorylation of specific tyrosine residues on beta-catenin/Armadillo. We will also determine whether endocytosis is important for regulating cell surface E-cadherin in migrating border cells. We will test whether Drosophila moesin contributes to E-cadherin dynamics. And we will investigate the mechanisms by which Myosin VI contributes to E-cadherin dynamics in border cells. In the second specific aim we propose to investigate in detail the mechanisms by which RhoGAP93B contributes to border cell migration by studying its biochemical activity, its expression pattern, subcellular localization, lethal phenotype and its regulation. Finally we propose to study a putative downstream target of Rho in border cells, rhophilin by characterizing the mutant phenotype, epistasis analysis with Rho and by identifying and characterizing interacting proteins.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM073164-02
Application #
7010356
Study Section
Special Emphasis Panel (ZRG1-DEV-1 (01))
Program Officer
Haynes, Susan R
Project Start
2005-02-01
Project End
2009-01-31
Budget Start
2006-02-01
Budget End
2007-01-31
Support Year
2
Fiscal Year
2006
Total Cost
$314,922
Indirect Cost
Name
Johns Hopkins University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
001910777
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Manning, Lathiena; Sheth, Jinal; Bridges, Stacey et al. (2017) A hormonal cue promotes timely follicle cell migration by modulating transcription profiles. Mech Dev 148:56-68
Dai, Wei; Montell, Denise J (2016) Live Imaging of Border Cell Migration in Drosophila. Methods Mol Biol 1407:153-68
Cho, Aeri; Kato, Masato; Whitwam, Tess et al. (2016) An Atypical Tropomyosin in Drosophila with Intermediate Filament-like Properties. Cell Rep 16:928-938
Prasad, Mohit; Wang, Xiaobo; He, Li et al. (2015) Border Cell Migration: A Model System for Live Imaging and Genetic Analysis of Collective Cell Movement. Methods Mol Biol 1328:89-97
Koride, Sarita; He, Li; Xiong, Li-Ping et al. (2014) Mechanochemical regulation of oscillatory follicle cell dynamics in the developing Drosophila egg chamber. Mol Biol Cell 25:3709-16
Cai, Danfeng; Chen, Shann-Ching; Prasad, Mohit et al. (2014) Mechanical feedback through E-cadherin promotes direction sensing during collective cell migration. Cell 157:1146-59
Pocha, Shirin M; Montell, Denise J (2014) Cellular and molecular mechanisms of single and collective cell migrations in Drosophila: themes and variations. Annu Rev Genet 48:295-318
Montell, Denise J (2013) Cell and molecular dynamics: visualizing, measuring, and manipulating the chemistry of life. Pflugers Arch 465:345-6
Ramel, Damien; Wang, Xiaobo; Laflamme, Carl et al. (2013) Rab11 regulates cell-cell communication during collective cell movements. Nat Cell Biol 15:317-24
Montell, Denise J; Yoon, Wan Hee; Starz-Gaiano, Michelle (2012) Group choreography: mechanisms orchestrating the collective movement of border cells. Nat Rev Mol Cell Biol 13:631-45

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