Perturbation of syndapin/PACSIN impairs synaptic vesicle recycling evoked by intense stimulation.
Synaptic vesicle recycling has been proposed to depend on proteins which coordinate membrane and cytoskeletal dynamics. Here, we examine the role of the dynamin- and N-WASP (neural Wiskott-Aldrich syndrome protein)-binding protein syndapin/PACSIN at the lamprey reticulospinal synapse. We find that presynaptic microinjection of syndapin antibodies inhibits vesicle recycling evoked by intense (5 Hz or more), but not by light (0.2 Hz) stimulation. This contrasts with the inhibition at light stimulation induced by perturbation of amphiphysin (Shupliakov et al., 1997). Inhibition by syndapin antibodies was associated with massive accumulation of membranous cisternae and invaginations around release sites, but not of coated pits at the plasma membrane. Cisternae contained vesicle membrane, as shown by vesicle-associated membrane protein 2 (VAMP2)/synaptobrevin 2 immunolabeling. Similar effects were observed when syndapin was perturbed before onset of massive endocytosis induced by preceding intense stimulation. Selective perturbation of the Src homology 3 domain interactions of syndapin was sufficient to induce vesicle depletion and accumulation of cisternae. Our data show an involvement of syndapin in synaptic vesicle recycling evoked by intense stimulation. We propose that syndapin is required to stabilize the plasma membrane and/or facilitate bulk endocytosis at high release rates.
Andersson
Fredrik
F
Department of Neuroscience, Karolinska Institutet, S-171 77 Stockholm, Sweden.
Jakobsson
Joel
J
Löw
Peter
P
Shupliakov
Oleg
O
Brodin
Lennart
L
D000199:Actins / Q000378:metabolism; D000818:Animals; D000906:Antibodies / Q000008:administration & dosage / Q000494:pharmacology; D001369:Axons / Q000502:physiology / Q000648:ultrastructure; D002352:Carrier Proteins / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D034281:Dynamins / Q000378:metabolism; D004558:Electric Stimulation / Q000379:methods; D004705:Endocytosis / Q000187:drug effects; D019706:Excitatory Postsynaptic Potentials / Q000187:drug effects; D007798:Lampreys; D008845:Microinjections; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000276:immunology / Q000502:physiology*; D017729:Presynaptic Terminals / Q000187:drug effects; D012154:Reticular Formation / Q000502:physiology / Q000648:ultrastructure; D013116:Spinal Cord / Q000502:physiology / Q000648:ultrastructure; D013569:Synapses / Q000187:drug effects / Q000502:physiology / Q000648:ultrastructure; D009435:Synaptic Transmission / Q000187:drug effects; D013572:Synaptic Vesicles / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D018909:src Homology Domains
D000199:Actins; D000906:Antibodies; D002352:Carrier Proteins; D009419:Nerve Tissue Proteins; D034281:Dynamins