L1-dependent neuritogenesis involves ankyrinB that mediates L1-CAM coupling with retrograde actin flow.
The cell adhesion molecule L1 (L1-CAM) plays critical roles in neurite growth. Its cytoplasmic domain (L1CD) binds to ankyrins that associate with the spectrin-actin network. This paper demonstrates that L1-CAM interactions with ankyrinB (but not with ankyrinG) are involved in the initial formation of neurites. In the membranous protrusions surrounding the soma before neuritogenesis, filamentous actin (F-actin) and ankyrinB continuously move toward the soma (retrograde flow). Bead-tracking experiments show that ankyrinB mediates L1-CAM coupling with retrograde F-actin flow in these perisomatic structures. Ligation of the L1-CAM ectodomain by an immobile substrate induces L1CD-ankyrinB binding and the formation of stationary ankyrinB clusters. Neurite initiation preferentially occurs at the site of these clusters. In contrast, ankyrinB is involved neither in L1-CAM coupling with F-actin flow in growth cones nor in L1-based neurite elongation. Our results indicate that ankyrinB promotes neurite initiation by acting as a component of the clutch module that transmits traction force generated by F-actin flow to the extracellular substrate via L1-CAM.
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Related Subject Headings
- Recombinant Fusion Proteins
- Protein Structure, Tertiary
- Protein Isoforms
- Neurons
- Neurites
- Neural Cell Adhesion Molecule L1
- Mice
- Humans
- Ganglia, Spinal
- Developmental Biology
Citation
Published In
DOI
ISSN
Publication Date
Volume
Issue
Start / End Page
Location
Related Subject Headings
- Recombinant Fusion Proteins
- Protein Structure, Tertiary
- Protein Isoforms
- Neurons
- Neurites
- Neural Cell Adhesion Molecule L1
- Mice
- Humans
- Ganglia, Spinal
- Developmental Biology