Actin assembly and non-muscle myosin activity drive dendrite retraction in an UNC-6/Netrin dependent self-avoidance response.

Sundararajan L, Smith CJ, Watson JD, Millis BA, Tyska MJ, Miller DM
PLoS Genet. 2019 15 (6): e1008228

PMID: 31220078 · PMCID: PMC6605669 · DOI:10.1371/journal.pgen.1008228

Dendrite growth is constrained by a self-avoidance response that induces retraction but the downstream pathways that balance these opposing mechanisms are unknown. We have proposed that the diffusible cue UNC-6(Netrin) is captured by UNC-40(DCC) for a short-range interaction with UNC-5 to trigger self-avoidance in the C. elegans PVD neuron. Here we report that the actin-polymerizing proteins UNC-34(Ena/VASP), WSP-1(WASP), UNC-73(Trio), MIG-10(Lamellipodin) and the Arp2/3 complex effect dendrite retraction in the self-avoidance response mediated by UNC-6(Netrin). The paradoxical idea that actin polymerization results in shorter rather than longer dendrites is explained by our finding that NMY-1 (non-muscle myosin II) is necessary for retraction and could therefore mediate this effect in a contractile mechanism. Our results also show that dendrite length is determined by the antagonistic effects on the actin cytoskeleton of separate sets of effectors for retraction mediated by UNC-6(Netrin) versus outgrowth promoted by the DMA-1 receptor. Thus, our findings suggest that the dendrite length depends on an intrinsic mechanism that balances distinct modes of actin assembly for growth versus retraction.

MeSH Terms (13)

Actin-Related Protein 2-3 Complex Actin Cytoskeleton Actins Animals Caenorhabditis elegans Caenorhabditis elegans Proteins Dendritic Cells Membrane Proteins Myosin Heavy Chains Nerve Tissue Proteins Netrins Neurons Nonmuscle Myosin Type IIB

Connections (1)

This publication is referenced by other Labnodes entities: