期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1990
卷号：87
期号：17
页码：6858-6862
DOI：10.1073/pnas.87.17.6858
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Recent studies in our laboratory have revealed the existence of an ATP- and calmodulin-dependent Ca2+ uptake system in rat liver nuclei that can promote increases in the free Ca2+ concentration in the nuclear matrix. In the present investigation we show that liver nuclei possess a marked ability to sequester and buffer Ca2+, suggesting a potential role for the nucleus in the regulation of the cytosolic free Ca2+ concentration. In addition, we demonstrate that the intracellular messenger, inositol 1,4,5-trisphosphate [Ins-(1,4,5)P3], stimulates the release of a fraction of the nuclear Ca2+ and transiently lowers the intranuclear free Ca2+ concentration. The Ins(1,4,5)P3-stimulated Ca2+ release is followed by Ca2+ reuptake into an inositol phosphate-insensitive nuclear compartment. Together, these results demonstrate that liver nuclei contain, at least, two Ca2+ pools, one of which is releasable by Ins(1,4,5)P3. These findings are consistent with a role for the nucleus in the modulation of the cytosolic free Ca2+ level by agonists and suggest that the control of the nuclear Ca2+ load by second messengers may participate in the regulation of intranuclear Ca2(+)-dependent processes by hormones and other agents.
