title: Using Bcr-Abl to examine mechanisms by which abl kinase regulates morphogenesis in Drosophila.
abstract: Signaling by the nonreceptor tyrosine kinase Abelson (Abl) plays key roles in normal development, whereas its inappropriate activation helps trigger the development of several forms of leukemia. Abl is best known for its roles in axon guidance, but Abl and its relatives also help regulate embryonic morphogenesis in epithelial tissues. Here, we explore the role of regulation of Abl kinase activity during development. We first compare the subcellular localization of Abl protein and of active Abl, by using a phosphospecific antibody, providing a catalog of places where Abl is activated. Next, we explore the consequences for morphogenesis of overexpressing wild-type Abl or expressing the activated form found in leukemia, Bcr-Abl. We find dose-dependent effects of elevating Abl activity on morphogenetic movements such as head involution and dorsal closure, on cell shape changes, on cell protrusive behavior, and on the organization of the actin cytoskeleton. Most of the effects of Abl activation parallel those caused by reduction in function of its target Enabled. Abl activation leads to changes in Enabled phosphorylation and localization, suggesting a mechanism of action. These data provide new insight into how regulated Abl activity helps direct normal development and into possible biological functions of Bcr-Abl.
authors.affiliation: Department of Biology and Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-3280, USA.
authors.forename: Traci L
authors.initials: TL
authors.lastname: Stevens
authors.forename: Edward M
authors.initials: EM
authors.lastname: Rogers
authors.forename: Laura M
authors.initials: LM
authors.lastname: Koontz
authors.forename: Donald T
authors.initials: DT
authors.lastname: Fox
authors.forename: Catarina C F
authors.initials: CC
authors.lastname: Homem
authors.forename: Stephanie H
authors.initials: SH
authors.lastname: Nowotarski
authors.forename: Nicholas B
authors.initials: NB
authors.lastname: Artabazon
authors.forename: Mark
authors.initials: M
authors.lastname: Peifer
mesh_terms: D000818:Animals; D048430:Cell Shape; D004268:DNA-Binding Proteins / Q000378:metabolism; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology* / Q000201:enzymology*; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000201:enzymology; D004789:Enzyme Activation; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000378:metabolism*; D008297:Male; D009024:Morphogenesis; D010766:Phosphorylation; D021381:Protein Transport; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011554:Pseudopodia / Q000201:enzymology; D020741:rho GTP-Binding Proteins / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C092744:ENA-VASP proteins; D011505:Protein-Tyrosine Kinases; C506548:Abl protein, Drosophila; D016044:Fusion Proteins, bcr-abl; D020741:rho GTP-Binding Proteins