Synaptotagmin I is necessary for compensatory synaptic vesicle endocytosis in vivo

K.E. Poskanzer; K.W. Marek; S.T. Sweeney; G.W. Davis

doi:10.1038/nature02184

Synaptotagmin I is necessary for compensatory synaptic vesicle endocytosis in vivo

K.E. Poskanzer, K.W. Marek, S.T. Sweeney, G.W. Davis

Biology

Research output: Contribution to journal › Article › peer-review

Abstract

Neurotransmission requires a balance of synaptic vesicle exocytosis and endocytosis1. Synaptotagmin I (Syt I) is widely regarded as the primary calcium sensor for synaptic vesicle exocytosis2, 3, 4, 5, 6. Previous biochemical data suggest that Syt I may also function during synaptic vesicle endocytosis7, 8, 9, 10, 11, 12, 13, 14, 15, 16; however, ultrastructural analyses at synapses with impaired Syt I function have provided an indirect and conflicting view of the role of Syt I during synaptic vesicle endocytosis3, 8, 9, 10, 14. Until now it has not been possible experimentally to separate the exocytic and endocytic functions of Syt I in vivo. Here, we test directly the role of Syt I during endocytosis in vivo. We use quantitative live imaging of a pH-sensitive green fluorescent protein fused to a synaptic vesicle protein (synapto-pHluorin) to measure the kinetics of endocytosis in sytI-null Drosophila. We then combine live imaging of the synapto-pHluorins with photoinactivation of Syt I, through fluorescein-assisted light inactivation, after normal Syt I-mediated vesicle exocytosis. By inactivating Syt I only during endocytosis, we demonstrate that Syt I is necessary for the endocytosis of synaptic vesicles that have undergone exocytosis using a functional Syt I protein.

Original language	English
Pages (from-to)	559-563
Number of pages	4
Journal	Nature
Volume	426
Issue number	6966
DOIs	https://doi.org/10.1038/nature02184
Publication status	Published - 2003

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10.1038/nature02184

http://dx.doi.org/10.1038/nature02184

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title = "Synaptotagmin I is necessary for compensatory synaptic vesicle endocytosis in vivo",

abstract = "Neurotransmission requires a balance of synaptic vesicle exocytosis and endocytosis1. Synaptotagmin I (Syt I) is widely regarded as the primary calcium sensor for synaptic vesicle exocytosis2, 3, 4, 5, 6. Previous biochemical data suggest that Syt I may also function during synaptic vesicle endocytosis7, 8, 9, 10, 11, 12, 13, 14, 15, 16; however, ultrastructural analyses at synapses with impaired Syt I function have provided an indirect and conflicting view of the role of Syt I during synaptic vesicle endocytosis3, 8, 9, 10, 14. Until now it has not been possible experimentally to separate the exocytic and endocytic functions of Syt I in vivo. Here, we test directly the role of Syt I during endocytosis in vivo. We use quantitative live imaging of a pH-sensitive green fluorescent protein fused to a synaptic vesicle protein (synapto-pHluorin) to measure the kinetics of endocytosis in sytI-null Drosophila. We then combine live imaging of the synapto-pHluorins with photoinactivation of Syt I, through fluorescein-assisted light inactivation, after normal Syt I-mediated vesicle exocytosis. By inactivating Syt I only during endocytosis, we demonstrate that Syt I is necessary for the endocytosis of synaptic vesicles that have undergone exocytosis using a functional Syt I protein.",

author = "K.E. Poskanzer and K.W. Marek and S.T. Sweeney and G.W. Davis",

year = "2003",

doi = "10.1038/nature02184",

language = "English",

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pages = "559--563",

journal = "Nature",

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T1 - Synaptotagmin I is necessary for compensatory synaptic vesicle endocytosis in vivo

AU - Poskanzer, K.E.

AU - Marek, K.W.

AU - Sweeney, S.T.

AU - Davis, G.W.

PY - 2003

Y1 - 2003

N2 - Neurotransmission requires a balance of synaptic vesicle exocytosis and endocytosis1. Synaptotagmin I (Syt I) is widely regarded as the primary calcium sensor for synaptic vesicle exocytosis2, 3, 4, 5, 6. Previous biochemical data suggest that Syt I may also function during synaptic vesicle endocytosis7, 8, 9, 10, 11, 12, 13, 14, 15, 16; however, ultrastructural analyses at synapses with impaired Syt I function have provided an indirect and conflicting view of the role of Syt I during synaptic vesicle endocytosis3, 8, 9, 10, 14. Until now it has not been possible experimentally to separate the exocytic and endocytic functions of Syt I in vivo. Here, we test directly the role of Syt I during endocytosis in vivo. We use quantitative live imaging of a pH-sensitive green fluorescent protein fused to a synaptic vesicle protein (synapto-pHluorin) to measure the kinetics of endocytosis in sytI-null Drosophila. We then combine live imaging of the synapto-pHluorins with photoinactivation of Syt I, through fluorescein-assisted light inactivation, after normal Syt I-mediated vesicle exocytosis. By inactivating Syt I only during endocytosis, we demonstrate that Syt I is necessary for the endocytosis of synaptic vesicles that have undergone exocytosis using a functional Syt I protein.

AB - Neurotransmission requires a balance of synaptic vesicle exocytosis and endocytosis1. Synaptotagmin I (Syt I) is widely regarded as the primary calcium sensor for synaptic vesicle exocytosis2, 3, 4, 5, 6. Previous biochemical data suggest that Syt I may also function during synaptic vesicle endocytosis7, 8, 9, 10, 11, 12, 13, 14, 15, 16; however, ultrastructural analyses at synapses with impaired Syt I function have provided an indirect and conflicting view of the role of Syt I during synaptic vesicle endocytosis3, 8, 9, 10, 14. Until now it has not been possible experimentally to separate the exocytic and endocytic functions of Syt I in vivo. Here, we test directly the role of Syt I during endocytosis in vivo. We use quantitative live imaging of a pH-sensitive green fluorescent protein fused to a synaptic vesicle protein (synapto-pHluorin) to measure the kinetics of endocytosis in sytI-null Drosophila. We then combine live imaging of the synapto-pHluorins with photoinactivation of Syt I, through fluorescein-assisted light inactivation, after normal Syt I-mediated vesicle exocytosis. By inactivating Syt I only during endocytosis, we demonstrate that Syt I is necessary for the endocytosis of synaptic vesicles that have undergone exocytosis using a functional Syt I protein.

U2 - 10.1038/nature02184

DO - 10.1038/nature02184

M3 - Article

VL - 426

SP - 559

EP - 563

JO - Nature

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