TY - JOUR
T1 - Open syntaxin overcomes exocytosis defects of diverse mutants in C. elegans
AU - Tien, Chi Wei
AU - Yu, Bin
AU - Huang, Mengjia
AU - Stepien, Karolina P.
AU - Sugita, Kyoko
AU - Xie, Xiaoyu
AU - Han, Liping
AU - Monnier, Philippe P.
AU - Zhen, Mei
AU - Rizo, Josep
AU - Gao, Shangbang
AU - Sugita, Shuzo
N1 - Funding Information:
This research was supported by the Natural Sciences and Engineering Research Council of Canada (RGPIN-2015-06438, to S.S.), the Canadian Institute of Health Research (MOP-130573 to S.S.), the Welch Foundation (I-1304 to J.R.) and the NIH (R35 NS097333 to J.R.), the National Natural Science Foundation of China (31871069 and 31671052 to S.G.), Major International (Regional) Joint Research Project (32020103007 to S.G.), the Junior Thousand Talents Program of China and funds from Huazhong University of Science and Technology (Dengfeng Initiative, Global Talents Recruitment Program). unc-10(md1117), unc-13(e51), (e1091), (n2813), unc-31(e928), unc-2(e55), unc-18(md299) (e81), and snt-1(md290) worms were provided from the Caenorhabditis Genetics Center (University of Minnesota). VC223 strain with a genotype of tom-1(ok285) was provided by the C. elegans Reverse Genetics Core Facility at the University of British Columbia, which is part of the international C. elegans Gene Knockout Consortium. pTX21 plasmid and anti-syntaxin-1 polyclonal antibody are kind gifts from Dr. Michael Nonet (Washington University) and Dr. Thomas C. Südhof (Stanford University), respectively. We also thank Dr. Thomas Südhof for comments on an earlier version of the draft. The summer scholarship for the Undergraduate Research Opportunity Program (UROP) from University of Toronto was awarded to C.-W.T. in 2016 and 2017.
Publisher Copyright:
© 2020, The Author(s).
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Assembly of SNARE complexes that mediate neurotransmitter release requires opening of a ‘closed’ conformation of UNC-64/syntaxin. Rescue of unc-13/Munc13 mutant phenotypes by overexpressed open UNC-64/syntaxin suggested a specific function of UNC-13/Munc13 in opening UNC-64/ syntaxin. Here, we revisit the effects of open unc-64/syntaxin by generating knockin (KI) worms. The KI animals exhibit enhanced spontaneous and evoked exocytosis compared to WT animals. Unexpectedly, the open syntaxin KI partially suppresses exocytosis defects of various mutants, including snt-1/synaptotagmin, unc-2/P/Q/N-type Ca2+ channel alpha-subunit and unc-31/CAPS, in addition to unc-13/Munc13 and unc-10/RIM, and enhanced exocytosis in tom-1/Tomosyn mutants. However, open syntaxin aggravates the defects of unc-18/Munc18 mutants. Correspondingly, open syntaxin partially bypasses the requirement of Munc13 but not Munc18 for liposome fusion. Our results show that facilitating opening of syntaxin enhances exocytosis in a wide range of genetic backgrounds, and may provide a general means to enhance synaptic transmission in normal and disease states.
AB - Assembly of SNARE complexes that mediate neurotransmitter release requires opening of a ‘closed’ conformation of UNC-64/syntaxin. Rescue of unc-13/Munc13 mutant phenotypes by overexpressed open UNC-64/syntaxin suggested a specific function of UNC-13/Munc13 in opening UNC-64/ syntaxin. Here, we revisit the effects of open unc-64/syntaxin by generating knockin (KI) worms. The KI animals exhibit enhanced spontaneous and evoked exocytosis compared to WT animals. Unexpectedly, the open syntaxin KI partially suppresses exocytosis defects of various mutants, including snt-1/synaptotagmin, unc-2/P/Q/N-type Ca2+ channel alpha-subunit and unc-31/CAPS, in addition to unc-13/Munc13 and unc-10/RIM, and enhanced exocytosis in tom-1/Tomosyn mutants. However, open syntaxin aggravates the defects of unc-18/Munc18 mutants. Correspondingly, open syntaxin partially bypasses the requirement of Munc13 but not Munc18 for liposome fusion. Our results show that facilitating opening of syntaxin enhances exocytosis in a wide range of genetic backgrounds, and may provide a general means to enhance synaptic transmission in normal and disease states.
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U2 - 10.1038/s41467-020-19178-x
DO - 10.1038/s41467-020-19178-x
M3 - Article
C2 - 33139696
AN - SCOPUS:85094897955
SN - 2041-1723
VL - 11
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 5516
ER -