Details

Autor(en) / Beteiligte

• Vigliarolo, Tiziana
• Guida, Lucrezia
• Millo, Enrico
• Fresia, Chiara
• Turco, Emilia
• De Flora, Antonio
• Zocchi, Elena

Titel

Abscisic Acid Transport in Human Erythrocytes

Ist Teil von

• The Journal of biological chemistry, 2015-05, Vol.290 (21), p.13042-13052

Ort / Verlag

United States: Elsevier Inc

Erscheinungsjahr

2015

Link zum Volltext

Quelle

MEDLINE

Beschreibungen/Notizen

• Abscisic acid (ABA) is a plant hormone involved in the response to environmental stress. Recently, ABA has been shown to be present and active also in mammals, where it stimulates the functional activity of innate immune cells, of mesenchymal and hemopoietic stem cells, and insulin-releasing pancreatic β-cells. LANCL2, the ABA receptor in mammalian cells, is a peripheral membrane protein that localizes at the intracellular side of the plasma membrane. Here we investigated the mechanism enabling ABA transport across the plasmamembrane of human red blood cells (RBC). Both influx and efflux of [3H]ABA occur across intact RBC, as detected by radiometric and chromatographic methods. ABA binds specifically to Band 3 (the RBC anion transporter), as determined by labeling of RBC membranes with biotinylated ABA. Proteoliposomes reconstituted with human purified Band 3 transport [3H]ABA and [35S]sulfate, and ABA transport is sensitive to the specific Band 3 inhibitor 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid. Once inside RBC, ABA stimulates ATP release through the LANCL2-mediated activation of adenylate cyclase. As ATP released from RBC is known to exert a vasodilator response, these results suggest a role for plasma ABA in the regulation of vascular tone. Background: The plant stress hormone abscisic acid (ABA) is present and active in mammalian cells. Results: Band 3 protein is required for ABA influx into red blood cells (RBC); intracellular ABA activates adenylate cyclase resulting in [cAMP]i increase and subsequent ATP release. Conclusion: ABA influx through Band 3 activates ATP release from RBC. Significance: Paracrine ABA may regulate the ATP-mediated vasodilator response to inflammation.