title: Bifocal is a downstream target of the Ste20-like serine/threonine kinase misshapen in regulating photoreceptor growth cone targeting in Drosophila.
abstract: Misshapen (Msn) has been proposed to shut down Drosophila photoreceptor (R cell) growth cone motility in response to targeting signals linked by the SH2/SH3 adaptor protein Dock. Here, we show that Bifocal (Bif), a putative cytoskeletal regulator, is a component of the Msn pathway for regulating R cell growth cone targeting. bif displays strong genetic interaction with msn. Phenotypic analysis indicates a specific role for Bif to terminate R1-R6 growth cones. Biochemical studies show that Msn associates directly with Bif and phosphorylates Bif in vitro. Cell culture studies demonstrate that Msn interacts with Bif to regulate F-actin structure and filopodium formation. We propose that Bif functions downstream of Msn to reorganize actin cytoskeleton in decelerating R cell growth cone motility at the target region.
authors.affiliation: McGill Centre for Research in Neuroscience, Montreal, Quebec, Canada.
authors.forename: Wenjing
authors.initials: W
authors.lastname: Ruan
authors.forename: Hong
authors.initials: H
authors.lastname: Long
authors.forename: Dac Hien
authors.initials: DH
authors.lastname: Vuong
authors.forename: Yong
authors.initials: Y
authors.lastname: Rao
mesh_terms: D000818:Animals; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins; D003599:Cytoskeleton / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology / Q000502:physiology*; D005136:Eye Proteins / Q000235:genetics / Q000378:metabolism*; D018628:Gene Dosage; D049452:Green Fluorescent Proteins; D020439:Growth Cones / Q000378:metabolism*; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology / Q000502:physiology; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D011554:Pseudopodia / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; D005136:Eye Proteins; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; C107943:bif protein, Drosophila; D049452:Green Fluorescent Proteins; C113875:msn protein, Drosophila; D017346:Protein Serine-Threonine Kinases