Work

Inositol 1,4,5-trisphosphate releases Ca2+ from a Ca2+-transporting membrane vesicle fraction derived from human platelets.

Year: 1985

Type: article

Abstract: Human platelet membrane vesicles that accumulated Ca2+ in the presence of ATP were isolated on an isoosmotic KCl-Percoll gradient. ATP-dependent Ca2+ uptake was stimulated by oxalate and phosphate to steady-state levels of greater than 100 nmol/mg protein, and the accumulated Ca2+ could be largely released by ionophore A23187. Inositol 1,4,5-trisphosphate, in a dose-dependent manner (0.5-5.0 microM), caused the rapid release (less than 5 s) of 40-70% of the total A23187-releasable store of accumulated Ca2+. The membrane vesicles that release accumulated Ca2+ in response to inositol 1,4,5-trisphosphate were enriched in enzymes characteristically found in smooth endoplasmic reticulum. These results support the hypothesis that inositol 1,4,5-trisphosphate, produced by the hydrolysis of phosphatidylinositol 1,4-bisphosphate in response to stimulation of cell surface receptors, is a second messenger mediating the release of Ca2+ from intracellular storage sites.

Source: Journal of Biological Chemistry

DOI: 10.1016/s0021-9258(20)71193-2

Authors: F A O'Rourke, S P Halenda, G B Zavoico, M B Feinstein

Institution: UConn Health

Language: English

Topic: Calcium signaling and nucleotide metabolism

Subfield: Physiology

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: hybrid

Estimated APC paid: $3,430

Funders: National Heart, Lung, and Blood Institute, National Institute of General Medical Sciences