Coordination of actin filament and microtubule dynamics during neurite outgrowth.
Although much evidence suggests that axon growth and guidance depend on well-coordinated cytoskeletal dynamics, direct characterization of the corresponding molecular events has remained a challenge. Here, we address this outstanding problem by examining neurite outgrowth stimulated by local application of cell adhesion substrates. During acute outgrowth, the advance of organelles and underlying microtubules was correlated with regions of attenuated retrograde actin network flow in the periphery. Interestingly, as adhesion sites matured, contractile actin arc structures, known to be regulated by the Rho/Rho Kinase/myosin II signaling cascade, became more robust and coordinated microtubule movements in the growth cone neck. When Rho Kinase was inhibited, although growth responses occurred with less of a delay, microtubules failed to consolidate into a single axis of growth. These results reveal a role for Rho Kinase and myosin II contractility in regulation of microtubule behavior during neuronal growth.
Schaefer
Andrew W
AW
Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511, USA.
Schoonderwoert
Vincent Th G
VT
Ji
Lin
L
Mederios
Nelson
N
Danuser
Gaudenz
G
Forscher
Paul
P
D008841:Actin Cytoskeleton / Q000502:physiology*; D000199:Actins / Q000502:physiology; D000577:Amides / Q000494:pharmacology; D000818:Animals; D001048:Aplysia / Q000166:cytology; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D003599:Cytoskeleton / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D020439:Growth Cones / Q000502:physiology; D007150:Immunohistochemistry; D008870:Microtubules / Q000378:metabolism*; D008959:Models, Neurological; D024462:Myosin Type II / Q000502:physiology; D016501:Neurites / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000502:physiology; D011725:Pyridines / Q000494:pharmacology; D013379:Substrate Specificity; D013997:Time Factors; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000502:physiology
D000199:Actins; D000577:Amides; D004791:Enzyme Inhibitors; D011725:Pyridines; C108830:Y 27632; D054460:rho-Associated Kinases; D024462:Myosin Type II