To The Editor:
This letter addresses the recent report by Abdullaev et al.1 In 2006, the seminal work of Feske and colleagues2 identified membrane proteins that were named Orais, after the Greek keepers of Heaven’s gate: Harmony (Orai1), Justice (Orai2), and Peace (Orai3). The proteins emerged through a study of severe combined immune deficiency (SCID), which is caused by a defect in Ca2+ entry of T lymphocytes. A mutation in the Orai1 gene underlies the defect.
There has been particular interest in Orais because of their relationship with the widely occurring store-operated Ca2+-entry (SOCE) phenomena, which reflect Ca2+-permeable plasma membrane mechanisms that respond to the depletion status of endoplasmic reticular Ca2+ stores. In lymphocytes, the store-operated mechanism is commonly observed as a Ca2+-selective and inwardly rectifying current, ICRAC. The mechanism is defective in SCID and rescued by expression of wild-type Orai1.2 In predicted structure Orais belong to the tetraspanin protein family3 rather than resembling known ion channels but mutations in Orais modify ion-selectivity, suggesting Orais generate ion permeation.4
Circulation Research. 2009;104:e22 [标签:content1][标签:content2]
作者:admin@医学,生命科学 2011-02-24 17:11