Genetic interaction between Neurexin and CAKI/CMG is important for synaptic function in Drosophila neuromuscular junction.
Neurexins are neuron-specific cell surface molecules thought to localize to presynaptic membranes. Recent genetic studies using Drosophila melanogaster have implicated an essential role for a single Drosophila neurexin (dnrx) in the proper architecture, development and function of synapses in vivo. However, the precise mechanisms underlying these actions are not fully understood. To elucidate the molecular mechanism of Neurexin in vivo, we employed dnrx and caki mutant flies, combined with various methods, and analyzed the animals' locomotion, synaptic vesicle cycling and neurotransmission of neuromuscular junctions. We found that Dneurexin (DNRX) is important for locomotion through a genetic interaction with the scaffold protein, CAKI/CMG, the Drosophila homolog of vertebrate CASK. Similar to its mammalian counterparts, DNRX is essential for synaptic vesicle cycling, which plays critical roles in neurotransmission at neuromuscular junctions (NMJ). However, this interaction appears not to be required for the synaptic targeting of DNRX, but may instead be needed for proper synaptic function, possibly by regulating the synaptic vesicle cycling process.
Sun
Mingkuan
M
Department of Genetics and Developmental Biology, Southeast University Medical School, The Key Laboratory of Developmental Genes and Human Disease, Ministry of Education, 87 Dingjiaqiao Road, Nanjing 210009, China.
Liu
Lijuan
L
Zeng
Xiankun
X
Xu
Min
M
Liu
Li
L
Fang
Ming
M
Xie
Wei
W
D000818:Animals; D030801:Animals, Genetically Modified; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000235:genetics* / Q000378:metabolism; D015816:Cell Adhesion Molecules, Neuronal / Q000235:genetics* / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D004705:Endocytosis / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D009043:Motor Activity / Q000235:genetics; D009154:Mutation / Q000235:genetics; D009469:Neuromuscular Junction / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000235:genetics; D021381:Protein Transport / Q000235:genetics; D013569:Synapses / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000235:genetics*; D013572:Synaptic Vesicles / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure
D015816:Cell Adhesion Molecules, Neuronal; D029721:Drosophila Proteins; C491321:Nrx protein, Drosophila; C099190:CASK protein, Drosophila; D017871:Calcium-Calmodulin-Dependent Protein Kinases