N-cadherin prodomain cleavage regulates synapse formation in vivo.
Cadherins are initially synthesized bearing a prodomain that is thought to limit adhesion during early stages of biosynthesis. Functional cadherins lack this prodomain, raising the intriguing possibility that cells may utilize prodomain cleavage as a means to temporally or spatially regulate adhesion after delivery of cadherin to the cell surface. In support of this idea, immunostaining for the prodomain of zebrafish N-cadherin revealed enriched labeling at neuronal surfaces at the soma and along axonal processes. To determine whether post-translational cleavage of the prodomain affects synapse formation, we imaged Rohon-Beard cells in zebrafish embryos expressing GFP-tagged wild-type N-cadherin (NCAD-GFP) or a GFP-tagged N-cadherin mutant expressing an uncleavable prodomain (PRON-GFP) rendering it nonadhesive. NCAD-GFP accumulated at synaptic microdomains in a developmentally regulated manner, and its overexpression transiently accelerated synapse formation. PRON-GFP was much more diffusely distributed along the axon and its overexpression delayed synapse formation. Our results support the notion that N-cadherin serves to stabilize pre- to postsynaptic contacts early in synapse development and suggests that regulated cleavage of the N-cadherin prodomain may be a mechanism by which the kinetics of synaptogenesis are regulated.
Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec, Canada H3A 2B4.
Nazlie S
NS
Latefi
Liliana
L
Pedraza
Anne
A
Schohl
Ziwei
Z
Li
Edward S
ES
Ruthazer
D000818:Animals; D001369:Axons / Q000378:metabolism / Q000648:ultrastructure; D001921:Brain / Q000166:cytology / Q000196:embryology* / Q000378:metabolism*; D015820:Cadherins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D009154:Mutation / Q000235:genetics; D009434:Neural Pathways / Q000196:embryology / Q000378:metabolism / Q000648:ultrastructure; D017434:Protein Structure, Tertiary / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013569:Synapses / Q000378:metabolism* / Q000648:ultrastructure; D013570:Synaptic Membranes / Q000378:metabolism / Q000648:ultrastructure; D015027:Zebrafish / Q000033:anatomy & histology / Q000196:embryology* / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
D015820:Cadherins; C513786:N-cadherin, zebrafish; D011993:Recombinant Fusion Proteins; D029961:Zebrafish Proteins; D049452:Green Fluorescent Proteins