1. Local traction force in the proximal leading process triggers nuclear translocation during neuronal migration.
- Author
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Umeshima H, Nomura KI, Yoshikawa S, Hörning M, Tanaka M, Sakuma S, Arai F, Kaneko M, and Kengaku M
- Subjects
- Actomyosin physiology, Animals, Biomechanical Phenomena, Cells, Cultured, Mice, Inbred ICR, Microscopy, Atomic Force, Cell Movement, Cell Nucleus physiology, Neurons physiology
- Abstract
Somal translocation in long bipolar neurons is regulated by actomyosin contractile forces, yet the precise spatiotemporal sites of force generation are unknown. Here we investigate the force dynamics generated during somal translocation using traction force microscopy. Neurons with a short leading process generated a traction force in the growth cone and counteracting forces in the leading and trailing processes. In contrast, neurons with a long leading process generated a force dipole with opposing traction forces in the proximal leading process during nuclear translocation. Transient accumulation of actin filaments was observed at the dipole center of the two opposing forces, which was abolished by inhibition of myosin II activity. A swelling in the leading process emerged and generated a traction force that pulled the nucleus when nuclear translocation was physically hampered. The traction force in the leading process swelling was uncoupled from somal translocation in neurons expressing a dominant negative mutant of the KASH protein, which disrupts the interaction between cytoskeletal components and the nuclear envelope. Our results suggest that the leading process is the site of generation of actomyosin-dependent traction force in long bipolar neurons, and that the traction force is transmitted to the nucleus via KASH proteins., (Copyright © 2018 Elsevier B.V. and Japan Neuroscience Society. All rights reserved.)
- Published
- 2019
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