The v-ATPase V0 subunit a1 is required for a late step in synaptic vesicle exocytosis in Drosophila

P Robin Hiesinger; Amir Fayyazuddin; Sunil Q Mehta; Tanja Rosenmund; Karen L Schulze; R Grace Zhai; Patrik Verstreken; Yu Cao; Yi Zhou; Jeannette Kunz; Hugo J Bellen

doi:10.1016/j.cell.2005.03.012

The v-ATPase V0 subunit a1 is required for a late step in synaptic vesicle exocytosis in Drosophila

Cell. 2005 May 20;121(4):607-620. doi: 10.1016/j.cell.2005.03.012.

Authors

Affiliations

¹ Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030.
² Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030.
³ Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030.
⁴ Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030.
⁵ Howard Hughes Medical Institute, Baylor College of Medicine, Houston, Texas 77030; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030; Program in Developmental Biology, Baylor College of Medicine, Houston, Texas 77030; Department of Neuroscience, Baylor College of Medicine, Houston, Texas 77030. Electronic address: hbellen@bcm.tmc.edu.

Abstract

The V(0) complex forms the proteolipid pore of an ATPase that acidifies vesicles. In addition, an independent function in membrane fusion has been proposed largely based on yeast vacuolar fusion experiments. We have isolated mutations in the largest V(0) component vha100-1 in flies in an unbiased genetic screen for synaptic malfunction. The protein is only required in neurons, colocalizes with markers for synaptic vesicles as well as active zones, and interacts with t-SNAREs. Loss of vha100-1 leads to vesicle accumulation in synaptic terminals, suggesting a deficit in release. The amplitude of spontaneous release events and release with hypertonic stimulation indicate normal levels of neurotransmitter loading, yet mutant embryos display severe defects in evoked synaptic transmission and FM1-43 uptake. Our data suggest that Vha100-1 functions downstream of SNAREs in synaptic vesicle fusion.

Publication types

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

MeSH terms

Animals
Drosophila melanogaster / metabolism*
Drosophila melanogaster / ultrastructure
Embryo, Nonmammalian / metabolism
Embryo, Nonmammalian / ultrastructure
Exocytosis / physiology*
Eye Abnormalities / genetics
Hypertonic Solutions / pharmacology
Membrane Fusion / physiology*
Microscopy, Electron
Mutation / genetics
Photoreceptor Cells, Invertebrate / abnormalities
Photoreceptor Cells, Invertebrate / ultrastructure
Protein Subunits / genetics
Protein Subunits / metabolism
Pyridinium Compounds / pharmacokinetics
Quaternary Ammonium Compounds / pharmacokinetics
SNARE Proteins
Synaptic Membranes / metabolism*
Synaptic Membranes / ultrastructure
Synaptic Transmission / genetics
Synaptic Vesicles / metabolism*
Synaptic Vesicles / ultrastructure
Vacuolar Proton-Translocating ATPases / genetics
Vacuolar Proton-Translocating ATPases / metabolism*
Vesicular Transport Proteins / metabolism

Substances

FM1 43
Hypertonic Solutions
Protein Subunits
Pyridinium Compounds
Quaternary Ammonium Compounds
SNARE Proteins
Vesicular Transport Proteins
Vacuolar Proton-Translocating ATPases

Abstract

Publication types

MeSH terms

Substances

Grants and funding