Open syntaxin overcomes exocytosis defects of diverse mutants in C. elegans

Chi-Wei Tien; Bin Yu; Mengjia Huang; Karolina P Stepien; Kyoko Sugita; Xiaoyu Xie; Liping Han; Philippe P Monnier; Mei Zhen; Josep Rizo; Shangbang Gao; Shuzo Sugita

doi:10.1038/s41467-020-19178-x

Open syntaxin overcomes exocytosis defects of diverse mutants in C. elegans

Nat Commun. 2020 Nov 2;11(1):5516. doi: 10.1038/s41467-020-19178-x.

Authors

Chi-Wei Tien^{1

2}, Bin Yu³, Mengjia Huang^{1

2}, Karolina P Stepien^{4

5

6}, Kyoko Sugita⁷, Xiaoyu Xie^{1

8}, Liping Han^{8

9}, Philippe P Monnier^{2

7

10}, Mei Zhen^{2

11

12}, Josep Rizo^{13

14

15}, Shangbang Gao¹⁶, Shuzo Sugita^{17

18}

Affiliations

¹ Division of Fundamental Neurobiology, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada, M5T 2S8.
² Faculty of Medicine, Department of Physiology, University of Toronto, Toronto, Ontario, Canada, M5S 1A8.
³ Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China.
⁴ Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
⁵ Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
⁶ Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
⁷ Division of Genetics and Development, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada, M5T 2S8.
⁸ Department of Anesthesiology, Dalian Medical University, Dalian, Liaoning, China.
⁹ Department of Anesthesiology, Dalian Municipal Friendship Hospital, Dalian Medical University, Dalian, Liaoning, China.
¹⁰ Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, Ontario, Canada, M5S 1A8.
¹¹ Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario, Canada, M5G 1X5.
¹² Faculty of Medicine, Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada, M5S 1A8.
¹³ Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, Texas, USA. Jose.rizo-rey@utsouthwestern.edu.
¹⁴ Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, Texas, USA. Jose.rizo-rey@utsouthwestern.edu.
¹⁵ Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas, USA. Jose.rizo-rey@utsouthwestern.edu.
¹⁶ Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science and Technology, Wuhan, 430074, China. sgao@hust.edu.cn.
¹⁷ Division of Fundamental Neurobiology, Krembil Brain Institute, University Health Network, Toronto, Ontario, Canada, M5T 2S8. Shuzo.Sugita@uhnresearch.ca.
¹⁸ Faculty of Medicine, Department of Physiology, University of Toronto, Toronto, Ontario, Canada, M5S 1A8. Shuzo.Sugita@uhnresearch.ca.

Abstract

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.

Publication types

Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

MeSH terms

Animals
Animals, Genetically Modified
Caenorhabditis elegans / genetics
Caenorhabditis elegans / metabolism*
Caenorhabditis elegans Proteins / genetics
Caenorhabditis elegans Proteins / metabolism*
Exocytosis / genetics*
Gene Knock-In Techniques
Liposomes / metabolism*
Mutation
Neurotransmitter Agents / metabolism
Synaptic Transmission / genetics*
Syntaxin 1 / genetics
Syntaxin 1 / metabolism*

Substances

Caenorhabditis elegans Proteins
Liposomes
Neurotransmitter Agents
Syntaxin 1
unc-64 protein, C elegans

Abstract

Publication types

MeSH terms

Substances

Grants and funding