The diversity of synaptotagmin isoforms

  title={The diversity of synaptotagmin isoforms},
  author={Anne C. Wolfes and Camin Dean},
  journal={Current Opinion in Neurobiology},

Function of Drosophila Synaptotagmins in membrane trafficking at synapses

The Drosophila SYT family is reviewed and several differences with the predicted activity of their mammalian counterparts are revealed, highlighting the remaining areas of uncertainty in the field and describing outstanding questions on how theSYT family regulates membrane trafficking at nerve terminals.

Expression and distribution of synaptotagmin isoforms in the zebrafish retina

Most zebrafish synaptotagmins are well conserved and can be grouped in the same classes as mammalian synaptoagmins, based on crucial amino acid residues needed for coordinating Ca2+ binding and determining phospholipid binding affinity.

Expression and distribution of synaptotagmin family members in the zebrafish retina

The homology between human, rat, mouse, and zebrafish synaptotagmins 1–10 is investigated using a bioinformatics approach and the complementary expression pattern of the remaining paralogues in the retina suggests that syt1a and syT5a may underlie synchronous release and syt7a and Syt7b may mediate asynchronous release or other Ca2+‐dependent processes in different retinal neurons.

Expression and distribution of synaptotagmin family members in the zebrafish retina.

The homology between human, rat, mouse, and zebrafish synaptotagmins 1 to 10 is investigated using a bioinformatics approach and the complementary expression pattern of the remaining paralogues in the retina suggests that syt1a and syt5a may underlie synchronous release and syT7a and Syt7b may mediate asynchronous release or other Ca2+ dependent processes in different retinal neurons.

Synaptotagmin 7 is targeted to the axonal plasma membrane through γ-secretase processing to promote synaptic vesicle docking in mouse hippocampal neurons

SYT7 is a peripheral membrane protein that controls multiple modes of synaptic vesicle (SV) exocytosis and plasticity, in part, through enhancing activity-dependent docking of SVs.

Synaptotagmin 7 outperforms synaptotagmin 1 to open and stabilize nascent fusion pores via robust membrane penetration

Using nanodisc-black lipid membrane electrophysiology, it is demonstrated that membrane penetration underlies the ability of syts to directly regulate reconstituted, exocytic fusion pores in response to Ca2+.

Conserved Arginine Residues in Synaptotagmin 1 Regulate Fusion Pore Expansion Through Membrane Contact

Data indicate that the C2B domain has at least two distinct molecular roles in the fusion event, and the data are consistent with a novel model where the arginine apex of C2 B positions the domain at the curved membrane surface of the expanding fusion pore.

Synaptotagmin 7 is enriched at the plasma membrane through γ-secretase processing to promote vesicle docking and control synaptic plasticity in mouse hippocampal neurons

This work used iGluSnFR to optically and directly interrogate glutamate release, at the single bouton level, in SYT7 KO dissociated mouse hippocampal neurons to analyze asynchronous release, paired pulse facilitation, and synaptic vesicle replenishment, and found thatSYT7 contributes to each of these processes to different degrees.

Synaptotagmin 9 modulates spontaneous neurotransmitter release in striatal neurons by regulating substance P secretion

It is concluded that SYT9 indirectly regulates synaptic transmission in striatal neurons by controlling SP release, a neuropeptide known to modulate mini frequency.



Synaptotagmins are trafficked to distinct subcellular domains including the postsynaptic compartment

The identification of a postsynaptic synaptotagmin suggests calcium-dependent membrane-trafficking functions on both sides of the synapse, and indicates that synaptoagmins are differentially distributed to unique subcellular compartments.

Synaptotagmin 17 controls neurite outgrowth and synaptic physiology via distinct cellular pathways

It is demonstrated that syt-17 exists in two distinct pools in hippocampal neurons (Golgi complex and early endosomes), where it served two completely independent functions: controlling neurite outgrowth and synaptic physiology.

Three distinct kinetic groupings of the synaptotagmin family: candidate sensors for rapid and delayed exocytosis.

Results indicate that syts have diverged to release Ca2+ and membranes with distinct kinetics, and isoforms of syt, which have much slower disassembly kinetics than does syt I, might function as Ca 2+ sensors for asynchronous release, which occurs after Ca2- domains have collapsed.

Analysis of the Synaptotagmin Family during Reconstituted Membrane Fusion

Biochemical analysis revealed a strong correlation between the ability of syt isoforms to bind 1,2-dioleoyl phosphatidylserine (PS) and t-SNAREs in a Ca2+-promoted manner with their abilities to enhance fusion, further establishing PS and SNAREs as critical effectors for syt action.

Calcium-dependent and -independent hetero-oligomerization in the synaptotagmin family.

It is shown that the synaptotagmin family is a type I membrane protein (N(lumen)/C(cytoplasm)) by introducing an artificial N-glycosylation site at the N-terminal domain, and data suggest that Ca(2+)-dependent and -independent hetero-oligomerization of synaptoagmins may create a variety of Ca( 2+)-sensors.

Distinct self-oligomerization activities of synaptotagmin family. Unique calcium-dependent oligomerization properties of synaptotagmin VII.

It is found that Syt VII is a unique class of synaptotagmins that only showed robust Ca(2+)-dependent self-oligomerization at the cytoplasmic domain with EC(50) values of about 150 micrometer Ca( 2+).

Distinct developmental expression of synaptotagmin I and IX in the mouse brain

The subcellular localization and developmental expression profile of synaptotagmin IX in the mouse brain is investigated and it is found that it is mainly present in the dense-core vesicle fraction, which is devoid ofsynapttagmin I and synaptophysin.

Synaptotagmin IV regulates glial glutamate release.

The finding that Syt IV is expressed predominantly by astrocytes and is not in the presynaptic terminals of the hippocampus, and because SytIV knockout mice exhibit hippocampal-based memory deficits, raises the intriguing possibility that SyT IV-mediated gliotransmission contributes to hippocampus-dependent memory.

Differential mRNA expression patterns of the synaptotagmin gene family in the rodent brain

It is demonstrated that most synaptotagmins are expressed in the rodent brain in highly distinctive expression patterns, and that individual neurons express variable subsets of different synapttagmins, and shows that Syt‐11 is the major isoform expressed in astrocytes.

The calcium sensor synaptotagmin 1 is expressed and regulated in hippocampal postsynaptic spines

In a rat model of chronic temporal lobe epilepsy, it is found that presynaptic and postsynaptic concentrations of the protein are reduced compared to control animals, and this downregulation may possibly be an adaptive measure to decrease both presynptic and post Synaptotagmin 1 calcium sensitivity in excitotoxic conditions.