کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
10926328 | 1091815 | 2013 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Bax Inhibitor-1-mediated Ca2+ leak is decreased by cytosolic acidosis
دانلود مقاله + سفارش ترجمه
دانلود مقاله ISI انگلیسی
رایگان برای ایرانیان
کلمات کلیدی
موضوعات مرتبط
علوم زیستی و بیوفناوری
بیوشیمی، ژنتیک و زیست شناسی مولکولی
بیولوژی سلول
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
Bax Inhibitor-1 (BI-1) is an evolutionarily conserved six-transmembrane domain endoplasmic reticulum (ER)-localized protein that protects against ER stress-induced apoptotic cell death. This function is closely connected to its ability to lower steady-state ER Ca2+ levels. Recently, we elucidated BI-1's Ca2+-channel pore in the C-terminal part of the protein and identified the critical amino acids of its pore. Based on these insights, a Ca2+-channel pore-dead mutant BI-1 (BI-1D213R) was developed. We determined whether BI-1 behaves as a bona fide H+/Ca2+ antiporter or as an ER Ca2+-leak channel by investigating the effect of pH on unidirectional Ca2+-efflux rates. At pH 6.8, wild-type BI-1 expression in BI-1â/â cells increased the ER Ca2+-leak rate, correlating with its localization in the ER compartment. In contrast, BI-1D231R expression in BI-1â/â, despite its ER localization, did not increase the ER Ca2+-leak rate. However, at pHÂ <Â 6.8, the BI-1-mediated ER Ca2+ leak was blocked. Finally, a peptide representing the Ca2+-channel pore of BI-1 promoting Ca2+ flux from the ER was used. Lowering the pH from 6.8 to 6.0 completely abolished the ability of the BI-1 peptide to mediate Ca2+ flux from the ER. We propose that this pH dependence is due to two aspartic acid residues critical for the function of the Ca2+-channel pore and located in the ER membrane-dipping domain, which facilitates the protonation of these residues.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Cell Calcium - Volume 54, Issue 3, September 2013, Pages 186-192
Journal: Cell Calcium - Volume 54, Issue 3, September 2013, Pages 186-192
نویسندگان
Santeri Kiviluoto, Tomas Luyten, Lars Schneider, Dmitrij Lisak, Diego Rojas-Rivera, Kirsten Welkenhuyzen, Ludwig Missaen, Humbert De Smedt, Jan B. Parys, Claudio Hetz, Axel Methner, Geert Bultynck,