期刊
CELL CALCIUM
卷 45, 期 2, 页码 123-132出版社
ELSEVIER SCI LTD
DOI: 10.1016/j.ceca.2008.07.005
关键词
Calcium homeostasis; Calcium signaling; Response curve; Competitive inhibition
类别
资金
- Dutch Science Foundation
- EU
- National Institute of Health, USA [GM053082]
Yeast can proliferate in environments containing very high Ca2+ primarily due to the activity of vacuolar Ca2+ transporters Pmc1 and Vcx1. Yeast mutants lacking these transporters fail to grow in high Ca2+ environments, but growth can be restored by small increases in environmental Mg2+. Low extracellular Mg2+ appeared to competitively inhibit novel Ca2+ influx pathways and to diminish the concentration of free Ca2+ in the cytoplasm, as judged from the luminescence of the photoprotein aequorin. These Mg2+-sensitive Ca2+ influx pathways persisted in yvc1 cch1 double mutants. Based on mathematical models of the aequorin luminescence traces, we propose the existence in yeast of at least two Ca2+ transporters that undergo rapid feedback inhibition in response to elevated cytosolic free Ca2+ concentration. Finally, we show that Vcx1 helps return cytosolic Ca2+ toward resting levels after shock with high extracellular Ca2+ much more effectively than Pmc1 and that calcineurin, a protein phosphatase regulator of Vcx1 and Pmc1, had no detectable effects on these factors within the first few minutes of its activation. Therefore, computational modeling of Ca2+ transport and signaling in yeast can provide important insights into the dynamics of this complex system. (C) 2008 Elsevier Ltd. All rights reserved.
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