UNC-115, A CONSERVED PROTEIN WITH PREDICTED LIM AND ACTIN-BINDING DOMAINS, MEDIATES AXON GUIDANCE IN C-ELEGANS

Axon guidance receptors modulate the growth cone cytoskeleton through signaling pathways that are not well understood. Here, we describe the C. elegans unc-115 gene, which encodes a candidate cytoskeletal linke r protein that acts in axon guidance, unc-115 mutants have defects in a subset of axons, particularly as the affected axons change environme nts during outgrowth. The unc-115 gene encodes a putative actin-bindin g protein that is similar to the human actin-binding protein abLIM/lim atin; it has a villin headpiece domain and three LIM domains that coul d mediate protein interactions. unc-115 is expressed in neurons during their development and is required cell-autonomously in certain neuron s for normal axon guidance. We propose that UNC-115 modulates the grow th cone actin cytoskeleton in response to signals received by growth c one receptors.