LIN-44/Wnt controls developmental neurite pruning via UNC-43/CaMKII and PKC-2/PKC in C. elegans

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Signaling

Background:

• Neuronal development involves extensive neurite pruning, with some events being stereotyped and developmentally regulated.
• The signaling pathways governing this form of neurite pruning are not fully understood.

Purpose of the Study:

• To investigate the molecular mechanisms underlying stereotyped neurite pruning in the PDB motor neuron of C. elegans.
• To identify the signaling pathways involved in developmentally regulated neurite pruning.

Main Methods:

• Utilized genetic analysis in C. elegans, focusing on mutants of IP3 receptor (itr-1) and calcium-dependent kinases (unc-43/CaMKII, pkc-2/PKC).
• Performed in vivo calcium imaging to observe calcium transients during neurite pruning.
• Investigated the role of Wnt signaling (lin-44) and clathrin-mediated endocytosis.

Main Results:

• Mutants lacking itr-1, unc-43, or pkc-2 displayed significant neurite pruning defects.
• lin-44/Wnt signaling acts upstream of these components in the pruning pathway.
• Calcium transients were observed in PDB neurites during pruning, regulated by lin-44 and itr-1.
• pkc-2 mediates neurite pruning via clathrin-mediated endocytosis.

Conclusions:

• The Wnt-calcium signaling pathway is essential for stereotyped neurite pruning during development.
• This pathway involves IP3 receptors, CaMKII, and PKC, functioning in a coordinated manner.
• The findings shed light on conserved mechanisms of neuronal remodeling and have implications for understanding neurodevelopmental disorders.