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Updated: Jul 6, 2026
13:16
Characterization of Membrane Transporters by Heterologous Expression in E. coli and Production of Membrane Vesicles
Published on: December 31, 2019
Identification of a vesicular nucleotide transporter
Keisuke Sawada1, Noriko Echigo, Narinobu Juge
1Department of Membrane Biochemistry, Okayama University Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan.
Summary
Researchers identified SLC17A9 as the protein responsible for storing adenosine triphosphate (ATP) in vesicles. This discovery clarifies the molecular mechanism behind ATP secretion in purinergic signaling.
Area of Science:
- Neuroscience
- Cell Biology
- Biochemistry
Background:
- Adenosine triphosphate (ATP) acts as a key chemical transmitter in purinergic signaling pathways.
- ATP is stored within secretory vesicles in purinergic cells before release.
- The specific proteins mediating ATP's vesicular accumulation have remained unidentified.
Purpose of the Study:
- To identify the protein responsible for vesicular ATP transport.
- To elucidate the molecular mechanism of ATP secretion in purinergic signaling.
Main Methods:
- Gene expression analysis of SLC17A9 in human and mouse tissues.
- Association studies of SLC17A9 with adrenal chromaffin granules.
- Functional characterization of purified SLC17A9 transporter in proteoliposomes.
- Assessment of ATP exocytosis following SLC17A9 suppression in PC12 cells.
Main Results:
- SLC17A9, a novel anion transporter family member, is predominantly expressed in the brain and adrenal gland.
- SLC17A9 is localized to adrenal chromaffin granules.
- Reconstituted SLC17A9 exhibits active uptake of ATP, ADP, and GTP, driven by membrane potential.
- Reduced SLC17A9 expression diminishes ATP exocytosis from PC12 cells.
Conclusions:
- SLC17A9 functions as a vesicular nucleotide transporter.
- This finding provides crucial insight into the molecular basis of ATP secretion in purinergic signaling.
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