Autonomous right-screw rotation of growth cone filopodia drives neurite turning.
The direction of neurite elongation is controlled by various environmental cues. However, it has been reported that even in the absence of any extrinsic directional signals, neurites turn clockwise on two-dimensional substrates. In this study, we have discovered autonomous rotational motility of the growth cone, which provides a cellular basis for inherent neurite turning. We have developed a technique for monitoring three-dimensional motility of growth cone filopodia and demonstrate that an individual filopodium rotates on its own longitudinal axis in the right-screw direction from the viewpoint of the growth cone body. We also show that the filopodial rotation involves myosins Va and Vb and may be driven by their spiral interactions with filamentous actin. Furthermore, we provide evidence that the unidirectional rotation of filopodia causes deflected neurite elongation, most likely via asymmetric positioning of the filopodia onto the substrate. Although the growth cone itself has been regarded as functionally symmetric, our study reveals the asymmetric nature of growth cone motility.
Tamada
Atsushi
A
Laboratory for Neuronal Growth Mechanisms, RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan. tamada@brain.riken.jp
Kawase
Satoshi
S
Murakami
Fujio
F
Kamiguchi
Hiroyuki
H
D000818:Animals; D005260:Female; D020439:Growth Cones / Q000378:metabolism*; D006801:Humans; D051379:Mice; D018995:Myosin Heavy Chains / Q000235:genetics / Q000378:metabolism; D024701:Myosin Type V / Q000235:genetics / Q000378:metabolism; D009218:Myosins / Q000235:genetics / Q000378:metabolism; D011247:Pregnancy; D011554:Pseudopodia / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
C505832:MYO5B protein, human; C513082:Myo5a protein, mouse; C513081:Myo5a protein, rat; C101826:Myo5b protein, rat; C077511:MYO5A protein, human; D024701:Myosin Type V; D018995:Myosin Heavy Chains; D009218:Myosins