PMID- 34408265
OWN - NLM
STAT- MEDLINE
DCOM- 20211203
LR  - 20211214
IS  - 2399-3642 (Electronic)
IS  - 2399-3642 (Linking)
VI  - 4
IP  - 1
DP  - 2021 Aug 18
TI  - The endosomal Q-SNARE, Syntaxin 7, defines a rapidly replenishing synaptic 
      vesicle recycling pool in hippocampal neurons.
PG  - 981
LID - 10.1038/s42003-021-02512-4 [doi]
LID - 981
AB  - Upon the arrival of repetitive stimulation at the presynaptic terminals of 
      neurons, replenishment of readily releasable synaptic vesicles (SVs) with 
      vesicles in the recycling pool is important for sustained neurotransmitter 
      release. Kinetics of replenishment and the available pool size define synaptic 
      performance. However, whether all SVs in the recycling pool are recruited for 
      release with equal probability and speed is unknown. Here, based on comprehensive 
      optical imaging of various presynaptic endosomal SNARE proteins in cultured 
      hippocampal neurons, all of which are implicated in organellar membrane fusion in 
      non-neuronal cells, we show that part of the recycling pool bearing the endosomal 
      Q-SNARE, syntaxin 7 (Stx7), is preferentially mobilized for release during 
      high-frequency repetitive stimulation. Recruitment of the SV pool marked with an 
      Stx7-reporter requires actin polymerization, as well as activation of the 
      Ca(2+)/calmodulin signaling pathway, reminiscent of rapidly replenishing SVs 
      characterized previously in calyx of Held synapses. Furthermore, disruption of 
      Stx7 function by overexpressing its N-terminal domain selectively abolished this 
      pool. Thus, our data indicate that endosomal membrane fusion involving Stx7 forms 
      rapidly replenishing vesicles essential for synaptic responses to high-frequency 
      repetitive stimulation, and also highlight functional diversities of endosomal 
      SNAREs in generating distinct exocytic vesicles in the presynaptic terminals.
CI  - (c) 2021. The Author(s).
FAU - Mori, Yasunori
AU  - Mori Y
AD  - Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha 
      University, Kyoto, Japan. yasmori@yamanashi.ac.jp.
AD  - Department of Biochemistry, Faculty of Medicine, University of Yamanashi, 
      Yamanashi, Japan. yasmori@yamanashi.ac.jp.
FAU - Takenaka, Koh-Ichiro
AU  - Takenaka KI
AD  - Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha 
      University, Kyoto, Japan.
FAU - Fukazawa, Yugo
AU  - Fukazawa Y
AUID- ORCID: 0000-0001-7436-8797
AD  - Division of Brain Structure and Function, Research Center for Child Mental 
      Development, Life Science Innovation Center, School of Medical Science, 
      University of Fukui, Fukui, Japan.
FAU - Takamori, Shigeo
AU  - Takamori S
AD  - Laboratory of Neural Membrane Biology, Graduate School of Brain Science, Doshisha 
      University, Kyoto, Japan. stakamor@mail.doshisha.ac.jp.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20210818
PL  - England
TA  - Commun Biol
JT  - Communications biology
JID - 101719179
RN  - 0 (Qa-SNARE Proteins)
SB  - IM
MH  - Animals
MH  - Endosomes/*metabolism
MH  - Hippocampus/*metabolism
MH  - Mice
MH  - Mice, Inbred ICR
MH  - Neurons/*metabolism
MH  - Qa-SNARE Proteins/*metabolism
MH  - Synaptic Vesicles/*metabolism
PMC - PMC8373932
COIS- The authors declare no competing interests.
EDAT- 2021/08/20 06:00
MHDA- 2021/12/15 06:00
PMCR- 2021/08/18
CRDT- 2021/08/19 06:30
PHST- 2020/08/22 00:00 [received]
PHST- 2021/08/02 00:00 [accepted]
PHST- 2021/08/19 06:30 [entrez]
PHST- 2021/08/20 06:00 [pubmed]
PHST- 2021/12/15 06:00 [medline]
PHST- 2021/08/18 00:00 [pmc-release]
AID - 10.1038/s42003-021-02512-4 [pii]
AID - 2512 [pii]
AID - 10.1038/s42003-021-02512-4 [doi]
PST - epublish
SO  - Commun Biol. 2021 Aug 18;4(1):981. doi: 10.1038/s42003-021-02512-4.