Synaptotagmin 1 directs repetitive release by coupling vesicle exocytosis to the Rab3 cycle
- Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, China
- University of Chinese Academy of Sciences, China
- Center for Excellence in Brain Science, Chinese Academy of Sciences, China
Figures
Figure 1 with 1 supplement
RAB-3 synaptic vesicle association requires SNT-1.
(A) Punctate distribution of GFP::RAB-3 in C. elegans motor neurons in wild-type animals (top). The GFP::RAB-3 puncta become diffuse in aex-3, rep-1, hmgs-1, and snt-1 mutants (lower panels). Yellow …
Figure 1—figure supplement 1
snt-1 is require for RAB-3 synaptic vesicle localization.
(A) Multiple snt-1 alleles show the diffuse GFP::RAB-3 phenotype. White arrows indicate the cell bodies. (B) GFP::RAB-3 expressed pan-neuronally under the control of the Prab-3 promoter displays …
Figure 2
Synaptic vesicle clustering is unaffected by loss of snt-1 function.
(A) SNB-1::GFP puncta distribution in wild type and snt-1 mutants. (B) The synaptic enrichment of SNB-1::GFP puncta is indistinguishable in wild type and snt-1. Data are presented as mean ± SD; NS, …
Figure 3
The GTP-bound form of RAB-3 is decreased in snt-1 mutants.
(A) A GST-fused RBD domain of RIM2 binds active GTP-RAB-3. The amount of GTP-RAB-3 pulled down by RBD is decreased in both aex-3 and snt-1 animals. (B) Quantification of the GTP-RAB-3 level in wild …
Figure 4 with 1 supplement
RAB-3 GAP mutations suppress the snt-1 mutant phenotype.
(A) The punctate distribution of GFP::RAB-3 is restored in rbg-1;snt-1 animals, while the aex-3 phenotype could not be suppressed by mutation of rbg-1. Yellow arrows indicate the cell bodies along …
Figure 4—figure supplement 1
rbg-2 suppresses the snt-1 mutant phenotype.
(A) Schematic representation of the rbg-1(ok1660) deletion mutation. (B) Schematic representation of the rbg-2(ok3195) deletion mutation. Solid boxes indicate exons and thin lines indicate introns. …
Figure 5
Localization of RBG-1 on synaptic vesicles requires SNT-1.
(A and B) mCherry::RBG-1 has a punctate distribution in wild type (A) but accumulates in cell bodies (yellow arrows) in unc-104 mutants (B). (C) mCherry::RBG-1 (red) is co-localized with SNB-1::GFP …
Figure 6
RBG-1 associates with the C2B domain of SNT-1.
(A) RBG-1 is precipitated by the intracellular domain (C2AB) of SNT-1. (B) The SNT-1 intracellular domain is precipitated by RBG-1. (C) The C2B domain of SNT-1 binds to RBG-1. (D) SNT-1 without the …
Figure 7 with 1 supplement
Dissociation of RAB-3 from synaptic vesicles requires the Ca2+-binding activity of SNT-1.
(A) Ca2+ treatment diminishes the binding between RBG-1 and the intracellular domain (C2AB) of SNT-1. (B) Quantification of the relative binding between RBG-1 and the C2AB domain upon Ca2+ …
Figure 7—figure supplement 1
Exocytosis is uncoupled from RAB-3 synaptic vesicle dissociation in snt-1 mutants.
(A) The failure of RAB-3/SV dissociation caused by exocytosis mutants, including unc-2 and unc-13, is bypassed by mutation of snt-1. Yellow arrows indicate the cell bodies along the ventral cord. …
