Abstract
The secretory pathway in neurons requires efficient targeting of cargos and regulatory proteins to their release sites. Tomosyn contributes to synapse function by regulating synaptic vesicle (SV) and dense-core vesicle (DCV) secretion. While there is large support for the presynaptic accumulation of tomosyn in fixed preparations, alternative subcellular locations have been suggested. Here we studied the dynamic distribution of tomosyn-1 (Stxbp5) and tomosyn-2 (Stxbp5l) in mouse hippocampal neurons and observed a mixed diffuse and punctate localization pattern of both isoforms. Tomosyn-1 accumulations were present in axons and dendrites. As expected, tomosyn-1 was expressed in about 75% of the presynaptic terminals. Interestingly, also bidirectional moving tomosyn-1 and -2 puncta were observed. Despite the lack of a membrane anchor these puncta co-migrated with synapsin and neuropeptide Y, markers for respectively SVs and DCVs. Genetic blockade of two known tomosyn interactions with synaptotagmin-1 and its cognate SNAREs did not abolish its vesicular co-migration, suggesting an interplay of protein interactions mediated by the WD40 and SNARE domains. We hypothesize that the vesicle-binding properties of tomosyns may control the delivery, pan-synaptic sharing and secretion of neuronal signaling molecules, exceeding its canonical role at the plasma membrane.
| Original language | English |
|---|---|
| Pages (from-to) | e0180912 |
| Journal | PLoS ONE |
| Volume | 12 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 2017 |
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Keywords
- Animals
- Axons
- Binding Sites
- Blotting, Western
- Cells, Cultured
- Dendrites
- Hippocampus
- Mice, Inbred C57BL
- Mice, Knockout
- Microscopy, Confocal
- Microscopy, Immunoelectron
- Nerve Tissue Proteins
- Neurons
- Neuropeptide Y
- Presynaptic Terminals
- Protein Binding
- Protein Transport
- R-SNARE Proteins
- Secretory Vesicles
- Synapsins
- Synaptic Vesicles
- Synaptotagmin I
- Journal Article
Cite this
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Tomosyn associates with secretory vesicles in neurons through its N- and C-terminal domains. / Geerts, Cornelia J; Mancini, Roberta; Chen, Ning; Koopmans, Frank T W; Li, Ka Wan; Smit, August B; van Weering, Jan R T; Verhage, Matthijs; Groffen, Alexander J A.
In: PLoS ONE, Vol. 12, No. 7, 2017, p. e0180912.Research output: Contribution to Journal › Article › Academic › peer-review
TY - JOUR
T1 - Tomosyn associates with secretory vesicles in neurons through its N- and C-terminal domains
AU - Geerts, Cornelia J
AU - Mancini, Roberta
AU - Chen, Ning
AU - Koopmans, Frank T W
AU - Li, Ka Wan
AU - Smit, August B
AU - van Weering, Jan R T
AU - Verhage, Matthijs
AU - Groffen, Alexander J A
PY - 2017
Y1 - 2017
N2 - The secretory pathway in neurons requires efficient targeting of cargos and regulatory proteins to their release sites. Tomosyn contributes to synapse function by regulating synaptic vesicle (SV) and dense-core vesicle (DCV) secretion. While there is large support for the presynaptic accumulation of tomosyn in fixed preparations, alternative subcellular locations have been suggested. Here we studied the dynamic distribution of tomosyn-1 (Stxbp5) and tomosyn-2 (Stxbp5l) in mouse hippocampal neurons and observed a mixed diffuse and punctate localization pattern of both isoforms. Tomosyn-1 accumulations were present in axons and dendrites. As expected, tomosyn-1 was expressed in about 75% of the presynaptic terminals. Interestingly, also bidirectional moving tomosyn-1 and -2 puncta were observed. Despite the lack of a membrane anchor these puncta co-migrated with synapsin and neuropeptide Y, markers for respectively SVs and DCVs. Genetic blockade of two known tomosyn interactions with synaptotagmin-1 and its cognate SNAREs did not abolish its vesicular co-migration, suggesting an interplay of protein interactions mediated by the WD40 and SNARE domains. We hypothesize that the vesicle-binding properties of tomosyns may control the delivery, pan-synaptic sharing and secretion of neuronal signaling molecules, exceeding its canonical role at the plasma membrane.
AB - The secretory pathway in neurons requires efficient targeting of cargos and regulatory proteins to their release sites. Tomosyn contributes to synapse function by regulating synaptic vesicle (SV) and dense-core vesicle (DCV) secretion. While there is large support for the presynaptic accumulation of tomosyn in fixed preparations, alternative subcellular locations have been suggested. Here we studied the dynamic distribution of tomosyn-1 (Stxbp5) and tomosyn-2 (Stxbp5l) in mouse hippocampal neurons and observed a mixed diffuse and punctate localization pattern of both isoforms. Tomosyn-1 accumulations were present in axons and dendrites. As expected, tomosyn-1 was expressed in about 75% of the presynaptic terminals. Interestingly, also bidirectional moving tomosyn-1 and -2 puncta were observed. Despite the lack of a membrane anchor these puncta co-migrated with synapsin and neuropeptide Y, markers for respectively SVs and DCVs. Genetic blockade of two known tomosyn interactions with synaptotagmin-1 and its cognate SNAREs did not abolish its vesicular co-migration, suggesting an interplay of protein interactions mediated by the WD40 and SNARE domains. We hypothesize that the vesicle-binding properties of tomosyns may control the delivery, pan-synaptic sharing and secretion of neuronal signaling molecules, exceeding its canonical role at the plasma membrane.
KW - Animals
KW - Axons
KW - Binding Sites
KW - Blotting, Western
KW - Cells, Cultured
KW - Dendrites
KW - Hippocampus
KW - Mice, Inbred C57BL
KW - Mice, Knockout
KW - Microscopy, Confocal
KW - Microscopy, Immunoelectron
KW - Nerve Tissue Proteins
KW - Neurons
KW - Neuropeptide Y
KW - Presynaptic Terminals
KW - Protein Binding
KW - Protein Transport
KW - R-SNARE Proteins
KW - Secretory Vesicles
KW - Synapsins
KW - Synaptic Vesicles
KW - Synaptotagmin I
KW - Journal Article
U2 - 10.1371/journal.pone.0180912
DO - 10.1371/journal.pone.0180912
M3 - Article
VL - 12
SP - e0180912
JO - PLoS ONE
JF - PLoS ONE
SN - 1932-6203
IS - 7
ER -