Regulated cell movements are dramatic features of normal animal development and are essential to the wound healing process, while deregulated motility results in deadly metastasis of tumor cells. To investigate the molecular mechanisms regulating the timing and direction of cell migration during development, we have been studying a small group of migratory follicle cells in the Drosophila ovary, referred to as border cells. One locus required for border cell migration is slow border cells (slbo), which encodes Drosophila C/EBP, a transcriptional regulator. Several putative downstream targets of c/EBP have been identified in the border cells, including a fibroblast growth factor receptor (FGFR) homolog, which is a receptor tyrosine kinase (RTK). RTK- mediated cell motility is a phenomenon of general interest and importance. To test the hypothesis that regulated FGFR activity guides cell migration, we propose to analyze the effects of expressing a constitutively active FGFR protein. To determine the importance of Ras signaling in the migration process, we propose to monitor changes in Ras activity during cell migration, using a fluorescent fusion protein that binds specifically to activated Ras. In order to elucidate the signaling pathway mediating the migration response, we propose to identify effectors of the FGFR. Proteins known to affect cell morphology in response to growth factor treatment of tissue culture cells are those of the Rho family of 21 kd GTPases. We have shown that the Rho family member Rac is essential to border cell migration whereas Cdc42 is not. We propose to determine which of the two Drosophila Rac proteins is required and to test whether Rho activity is also essential for the migration. A second putative target of slbo in the border cells is defined by enhancer trap insertion dts3. Reporter gene expression in this line is at highest levels in the border cells and in the oocyte, the cell towards which the border cells migrate. In a slbo mutant background, the border cell expression of this line is greatly reduced. Furthermore mutant alleles of this locus display border cell migration defects. We have cloned and sequenced cDNAs from the locus. We propose to test whether graded expression of this novel 1107 amino acid protein, along the migration path, is essential to the migration process. We also propose to test the hypotheses that Dts3 associates with the cytoskeleton and is regulated by tyrosine phosphorylation.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM046425-09
Application #
6018859
Study Section
Cellular Biology and Physiology Subcommittee 1 (CBY)
Project Start
1991-08-01
Project End
2000-07-31
Budget Start
1999-08-01
Budget End
2000-07-31
Support Year
9
Fiscal Year
1999
Total Cost
Indirect Cost
Name
Johns Hopkins University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218
Campanale, Joseph P; Sun, Thomas Y; Montell, Denise J (2017) Development and dynamics of cell polarity at a glance. J Cell Sci 130:1201-1207
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
Cai, Danfeng; Dai, Wei; Prasad, Mohit et al. (2016) Modeling and analysis of collective cell migration in an in vivo three-dimensional environment. Proc Natl Acad Sci U S A 113:E2134-41
Xiang, Wenjuan; Zhang, Dabing; Montell, Denise J (2016) Tousled-like kinase regulates cytokine-mediated communication between cooperating cell types during collective border cell migration. Mol Biol Cell 27:12-9
Ding, Austin Xun; Sun, Gongping; Argaw, Yewubdar G et al. (2016) CasExpress reveals widespread and diverse patterns of cell survival of caspase-3 activation during development in vivo. Elife 5:
Cai, Danfeng; Montell, Denise J (2014) Diverse and dynamic sources and sinks in gradient formation and directed migration. Curr Opin Cell Biol 30:91-8
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
Montell, Denise J (2013) Cell and molecular dynamics: visualizing, measuring, and manipulating the chemistry of life. Pflugers Arch 465:345-6
Chang, Yu-Chiuan; Jang, Anna C-C; Lin, Cheng-Han et al. (2013) Castor is required for Hedgehog-dependent cell-fate specification and follicle stem cell maintenance in Drosophila oogenesis. Proc Natl Acad Sci U S A 110:E1734-42

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