Distinct roles of calcineurin-nuclear factor of activated T-cells and protein kinase A-cAMP response element-binding protein signaling in presynaptic differentiation.
Synaptic vesicle accumulation and morphological changes are characteristic features of axon terminal differentiation during synaptogenesis. To investigate the regulatory mechanism that orchestrates synaptic molecules to form mature presynaptic terminals, we visualized a single axon terminal of zebrafish olfactory sensory neurons in vivo and examined the effects of the neuron-specific gene manipulations on the axon terminal differentiation. Synaptic vesicles visualized with vesicle-associated membrane protein 2 (VAMP2)-enhanced green fluorescent protein (EGFP) fusion protein gradually accumulated in axon terminals, whereas the axon terminals visualized with GAP43 fused with EGFP remodeled from complex shapes with filopodia to simple shapes without filopodia from 50 h postfertilization (hpf) to 84 hpf. Expression of dominant-negative protein kinase A (PKA) or cAMP response element-binding protein (CREB) suppressed the VAMP2-EGFP punctum formation in axon terminals during synaptogenesis. Consistently, constitutively active PKA or CREB stimulated VAMP2-EGFP puncta formation. On the other hand, cyclosporine A treatment or suppression of nuclear factor of activated T cells (NFAT) activation prevented the axon terminal remodeling from complex to simple shapes during synaptogenesis. Consistently, expression of constitutively active calcineurin accelerated the axon terminal remodeling. These results suggest that calcineurin-NFAT signaling regulates axon terminal remodeling, and PKA-CREB signaling controls synaptic vesicle accumulation.
Yoshida
Tomoyuki
T
Department of Molecular Neurobiology and Pharmacology, Graduate School of Medicine, University of Tokyo, and Solution-Oriented Research for Science and Technology, Japan Science and Technology Corporation, Tokyo 113-0033, Japan.
Mishina
Masayoshi
M
D000367:Age Factors; D000818:Animals; D030801:Animals, Genetically Modified; D019703:Calcineurin / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology*; D016572:Cyclosporine / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000235:genetics; D003952:Diagnostic Imaging; D004625:Embryo, Nonmammalian; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019922:GAP-43 Protein / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D049452:Green Fluorescent Proteins / Q000096:biosynthesis / Q000235:genetics; D007150:Immunohistochemistry / Q000379:methods; D008845:Microinjections / Q000379:methods; D050778:NFATC Transcription Factors / Q000502:physiology*; D018034:Olfactory Receptor Neurons / Q000196:embryology / Q000378:metabolism; D017729:Presynaptic Terminals / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D015398:Signal Transduction / Q000502:physiology*; D020825:T-Box Domain Proteins; D050988:Vesicle-Associated Membrane Protein 2 / Q000378:metabolism; D015027:Zebrafish; D029961:Zebrafish Proteins / Q000235:genetics
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D019922:GAP-43 Protein; D050778:NFATC Transcription Factors; D012333:RNA, Messenger; D020825:T-Box Domain Proteins; D050988:Vesicle-Associated Membrane Protein 2; D029961:Zebrafish Proteins; C119156:tbr1b protein, zebrafish; D049452:Green Fluorescent Proteins; D016572:Cyclosporine; D017868:Cyclic AMP-Dependent Protein Kinases; D019703:Calcineurin