ENU-3 is a new player in UNC-6/Netrin directed axon outgrowth and guidance in C. elegans

UNC-6/Netrin is an axon guidance cue that works through UNC-40/DCC/Frazzled to attract cells and neurons and through UNC-5 and UNC-40 to repulse cells and neurons during nervous system development. The gene encoding the novel protein ENU-3 was identified in a mutant that enhanced the axon outgrowth defects of the DA and DB classes of motor neurons in a strain lacking functional UNC-5. Mutant ENU-3 also enhanced the axon outgrowth and guidance defects of the ventrally directed processes of the AVM and PVM touch receptor neurons in a strain lacking functional UNC-40. ENU-3 also plays a role in adhesion of axons to the substratum as does UNC-40. The protein is a putative single pass transmembrane protein expressed throughout the nervous system whose possible biochemical roles are currently unknown.