학술논문
Orai-2 is localized on secretory granules and regulates antigen-evoked Ca2+ mobilization and exocytosis in mast cells.
Document Type
Article
Author
Source
Subject
*ANTIGENS
*CALCIUM ions
*EXOCYTOSIS
*MAST cells
*ALLERGIES
*CALCIUM channels
*
*
*
*
*
Language
ISSN
0006-291X
Abstract
The increase in intracellular Ca 2+ through the Ca 2+ channel is an indispensable step for the secretion of inflammatory mediators by mast cells. It was recently reported that Orai-1 is responsible for the Ca 2+ influx that is activated by depletion of stored Ca 2+ . There are three isoforms of Orai: Orai-1, Orai-2, and Orai-3; however, isoforms other than Orai-1 are poorly understood. We found that Orai-2 is expressed and localized on secretory granules in RBL-2H3. Ca 2+ release from Ca 2+ store, induced by antigen stimulation, was significantly attenuated by knockdown of Orai-2, while that induced by thapsigargin was not affected. Furthermore, exocytotic release induced by antigen stimulation was inhibited in knockdown cells. This observation suggests a new role of Orai isoforms in secretory cells. [ABSTRACT FROM AUTHOR]