A multi-protein receptor-ligand complex underlies combinatorial dendrite guidance choices in C. elegans

• Main Authors: Wei Zou, Ao Shen, Xintong Dong, Madina Tugizova, Yang K Xiang, Kang Shen
• Format: Article
• Language: English
• Published: eLife Sciences Publications Ltd 2016-10-01
• Series: eLife
• Subjects: dendrite guidance; ligand-receptor interaction; cell-cell adhesion
• Online Access: https://elifesciences.org/articles/18345

Ligand receptor interactions instruct axon guidance during development. How dendrites are guided to specific targets is less understood. The C. elegans PVD sensory neuron innervates muscle-skin interface with its elaborate dendritic branches. Here, we found that LECT-2, the ortholog of leukocyte cell-derived chemotaxin-2 (LECT2), is secreted from the muscles and required for muscle innervation by PVD. Mosaic analyses showed that LECT-2 acted locally to guide the growth of terminal branches. Ectopic expression of LECT-2 from seam cells is sufficient to redirect the PVD dendrites onto seam cells. LECT-2 functions in a multi-protein receptor-ligand complex that also contains two transmembrane ligands on the skin, SAX-7/L1CAM and MNR-1, and the neuronal transmembrane receptor DMA-1. LECT-2 greatly enhances the binding between SAX-7, MNR-1 and DMA-1. The activation of DMA-1 strictly requires all three ligands, which establishes a combinatorial code to precisely target and pattern dendritic arbors.