Interaction Between Drosophila Neuroligin1 And Neuroligin3 Regulates Neuromuscular Junction Development And Function

Neuroligins are a family of postsynaptic cell adhesion molecules that can bind to presynaptic Neurexin,and the transsynaptic complex was thought to be important for synapse formation and function.Human genetic studies have also indicated that Neuroligins are linked to a number of neurodevelopment and mental disorders such as autism.There are four Neuroligins(DNlgl?4)in Drosohila neuromuscular junction.Several studies have reported the role of DNlgl-3 in synaptic development and function and the role of DNlg4 in sleep.However,relationships among different DNlgs remain unclear.In this study,we explored the relationships between DNlgl and other three DNlg3.When overexpressing DNlgl-EGFP in dnlg2,dnlg3 and dnlg4 mutants respectively by using muscle specific Gal4,we found that protein DNlgl-EGFP indnlg2 mutant increased compared to WT control.Due to the studies reported that DNlg1 and DNlg2 have similar functions,this result suggests that the relationship between DNlgl and DNlg2 is compensation.In addition,we found that overexpressing DNlgl-EGFP in dnlg3 mutant caused death in pupae and it can be rescued by decreasing DNlgl-EGFP protein level and increasing DNlg3 protein level.This result indicates that the interaction between DNlgl and DNlg3 is important for NMJ development and function.Further,we explored the mechanism and found that interaction between DNlgl and DNlg3 plays a role in reorganization of NMJ during metamorphosis.