期刊
JOURNAL OF PHYSIOLOGY-LONDON
卷 553, 期 3, 页码 775-788出版社
WILEY
DOI: 10.1113/jphysiol.2003.054247
关键词
-
资金
- NIGMS NIH HHS [R01 GM048071, GM58329, GM48071, R37 GM048071] Funding Source: Medline
Ca2+ liberation through inositol 1,4,5-trisphosphate receptors (IP(3)Rs) plays a universal role in cell regulation, and specificity of cell signalling is achieved through the spatiotemporal patterning of Ca2+ signals. IP(3)Rs display Ca2+-induced Ca2+ release (CICR), but are grouped in clusters so that regenerative Ca2+ signals may remain localized to individual clusters, or propagate globally between clusters by successive cycles of Ca2+ diffusion and CICR. We used confocal microscopy and photoreleased IP3 in Xenopus oocytes to study how these properties are modulated by mobile cytosolic Ca2+ buffers. EGTA (a buffer with slow 'on-rate') speeded Ca2+ signals and 'balkanized' Ca2+ waves by dissociating them into local signals. In contrast, BAPTA (a fast buffer with similar affinity) slowed Ca2+ responses and promoted 'globalization' of spatially uniform Ca2+ signals. These actions are likely to arise through differential effects on Ca2+ feedback within and between IP3R clusters, because Ca2+ signals evoked by influx through voltage-gated channels were little affected. We propose that cell-specific expression of Ca2+-binding proteins with distinct kinetics may shape the time course and spatial distribution Of IP3-evoked Ca2+ signals for specific physiological roles.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据