Open Close
Reference
Citation
Saraswati, S., Adolfsen, B., Littleton, J.T. (2007). Characterization of the role of the Synaptotagmin family as calcium sensors in facilitation and asynchronous neurotransmitter release.  Proc. Natl. Acad. Sci. U.S.A. 104(35): 14122--14127.
FlyBase ID
FBrf0201175
Publication Type
Research paper
Abstract

Ca(2+) influx into presynaptic nerve terminals activates synaptic vesicle exocytosis by triggering fast synchronous fusion and a slower asynchronous release pathway. In addition, a brief rise in Ca(2+) after consecutive action potentials has been correlated with a form of short-term synaptic plasticity with enhanced vesicle fusion termed facilitation. Although the synaptic vesicle protein Synaptotagmin 1 (Syt1) has been implicated as the Ca(2+) sensor for synchronous fusion, the molecular identity of the Ca(2+) sensors that mediate facilitation and asynchronous release is unknown. To test whether the synchronous Ca(2+) sensor, Syt1, or the asynchronous Ca(2+) sensor is involved in facilitation, we analyzed whether genetic elimination of Syt1 in Drosophila results in a concomitant impairment in facilitation. Our results indicate that Syt1 acts as a redundant Ca(2+) sensor for facilitation, with the asynchronous Ca(2+) sensor contributing significantly to this form of short-term plasticity. We next examined whether other members of the Drosophila Syt family functioned in Ca(2+)-dependent asynchronous release or facilitation in vivo. Genetic elimination of other panneuronally expressed Syt proteins did not alter these forms of exocytosis, indicating a non-Syt Ca(2+) sensor functions for both facilitation and asynchronous release. In light of these findings, the presence of two presynaptic Ca(2+) sensors can be placed in a biological context, a Syt1-based Ca(2+) sensor devoted primarily to baseline synaptic transmission and a second non-Syt Ca(2+) sensor for short-term synaptic plasticity and asynchronous release.

PubMed ID
PubMed Central ID
PMC1955806 (PMC) (EuropePMC)
Associated Information
Comments
Associated Files
Other Information
Secondary IDs
    Language of Publication
    English
    Additional Languages of Abstract
    Parent Publication
    Publication Type
    Journal
    Abbreviation
    Proc. Natl. Acad. Sci. U.S.A.
    Title
    Proceedings of the National Academy of Sciences of the United States of America
    Publication Year
    1915-
    ISBN/ISSN
    0027-8424
    Data From Reference
    Alleles (7)
    Genes (4)
    Natural transposons (1)
    Insertions (1)
    Experimental Tools (2)
    Transgenic Constructs (3)