title: Leading-process actomyosin coordinates organelle positioning and adhesion receptor dynamics in radially migrating cerebellar granule neurons.
abstract: BACKGROUND
  During brain development, neurons migrate from germinal zones to their final positions to assemble neural circuits. A unique saltatory cadence involving cyclical organelle movement (e.g., centrosome motility) and leading-process actomyosin enrichment prior to nucleokinesis organizes neuronal migration. While functional evidence suggests that leading-process actomyosin is essential for centrosome motility, the role of the actin-enriched leading process in globally organizing organelle transport or traction forces remains unexplored.
  
  
  RESULTS
  We show that myosin ii motors and F-actin dynamics are required for Golgi apparatus positioning before nucleokinesis in cerebellar granule neurons (CGNs) migrating along glial fibers. Moreover, we show that primary cilia are motile organelles, localized to the leading-process F-actin-rich domain and immobilized by pharmacological inhibition of myosin ii and F-actin dynamics. Finally, leading process adhesion dynamics are dependent on myosin ii and F-actin.
  
  
  CONCLUSIONS
  We propose that actomyosin coordinates the overall polarity of migrating CGNs by controlling asymmetric organelle positioning and cell-cell contacts as these cells move along their glial guides.
authors.forename: Niraj
authors.initials: N
authors.lastname: Trivedi
authors.forename: Joseph S
authors.initials: JS
authors.lastname: Ramahi
authors.forename: Mahmut
authors.initials: M
authors.lastname: Karakaya
authors.forename: Danielle
authors.initials: D
authors.lastname: Howell
authors.affiliation: Department of Developmental Neurobiology, St, Jude Children's Research Hospital, 262 Danny Thomas Place, Memphis, TN 38105, USA. kerekesra@ornl.gov.
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Kerekes
authors.forename: David J
authors.initials: DJ
authors.lastname: Solecki
mesh_terms: D000199:Actins / Q000378:metabolism; D000205:Actomyosin / Q000378:metabolism*; D000818:Animals; D002465:Cell Movement; D016764:Cell Polarity; D002531:Cerebellum / Q000166:cytology*; D006056:Golgi Apparatus / Q000378:metabolism / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D024462:Myosin Type II / Q000378:metabolism; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure*; D019038:Platelet Glycoprotein GPIb-IX Complex / Q000378:metabolism*
chemical_list: D000199:Actins; D019038:Platelet Glycoprotein GPIb-IX Complex; C094990:adhesion receptor; D000205:Actomyosin; D024462:Myosin Type II