Unknown

Dataset Information

0

Synaptotagmin-1 and Doc2b Exhibit Distinct Membrane-Remodeling Mechanisms.


ABSTRACT: Synaptotagmin-1 (Syt1) is a calcium sensor protein that is critical for neurotransmission and is therefore extensively studied. Here, we use pairs of optically trapped beads coated with SNARE-free synthetic membranes to investigate Syt1-induced membrane remodeling. This activity is compared with that of Doc2b, which contains a conserved C2AB domain and induces membrane tethering and hemifusion in this cell-free model. We find that the soluble C2AB domain of Syt1 strongly affects the probability and strength of membrane-membrane interactions in a strictly Ca2+- and protein-dependent manner. Single-membrane loading of Syt1 yielded the highest probability and force of membrane interactions, whereas in contrast, Doc2b was more effective after loading both membranes. A lipid-mixing assay with confocal imaging reveals that both Syt1 and Doc2b are able to induce hemifusion; however, significantly higher Syt1 concentrations are required. Consistently, both C2AB fragments cause a reduction in the membrane-bending modulus, as measured by a method based on atomic force microscopy. This lowering of the energy required for membrane deformation may contribute to Ca2+-induced fusion.

SUBMITTER: Sorkin R 

PROVIDER: S-EPMC7002981 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

altmetric image

Publications


Synaptotagmin-1 (Syt1) is a calcium sensor protein that is critical for neurotransmission and is therefore extensively studied. Here, we use pairs of optically trapped beads coated with SNARE-free synthetic membranes to investigate Syt1-induced membrane remodeling. This activity is compared with that of Doc2b, which contains a conserved C<sub>2</sub>AB domain and induces membrane tethering and hemifusion in this cell-free model. We find that the soluble C<sub>2</sub>AB domain of Syt1 strongly af  ...[more]

Similar Datasets

| S-EPMC5300960 | biostudies-literature
| S-EPMC2712455 | biostudies-literature
| S-EPMC4849160 | biostudies-literature
| S-EPMC5758110 | biostudies-literature
| S-EPMC2723061 | biostudies-literature
| S-EPMC10862756 | biostudies-literature
| S-EPMC5512084 | biostudies-literature
| S-EPMC1237081 | biostudies-literature
| S-EPMC7415960 | biostudies-literature
| S-EPMC4142614 | biostudies-literature