Dynamics of the distribution of cyclic AMP-dependent protein kinase in living cells.
Dynamics of the distribution of cyclic AMP-dependent protein kinase in living cells.
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活细胞中环AMP依赖性蛋白激酶分布的动态。
DOI：
10.1073/pnas.87.24.9595
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发表时间：
1990
影响因子：
11.1
通讯作者：
J. Feramisco
中科院分区：
文献类型：
--
作者：
J. Meinkoth;Ying;S. Taylor;J. Feramisco
调节分子的细胞内分布可以提供用于控制基因表达的机制。通过显微注射荧光素标记的调节和催化亚基，在活细胞中分析cAMP依赖性蛋白激酶的亚细胞定位。显微注射后，I型全酶被发现在细胞质中，并留在那里长达4 hr. Upon解离全酶与8-溴-cAMP，游离的催化亚基出现在细胞核中，而调节亚基留在细胞质中。类似地，纯化的催化亚基在其引入细胞质后在不存在升高的细胞内cAMP的情况下被转运至细胞核。易位到细胞核是明显的10分钟内，并持续至少2小时。相反，纯化的调节亚基，如全酶，保持在细胞质中。这些结果表明，I型调节亚基的功能之一是作为细胞质的锚，在细胞质中隔离催化亚基，直到全酶解离响应增加cAMP。
The intracellular distribution of regulatory molecules may provide a mechanism for controlling gene expression. The subcellular location of cAMP-dependent protein kinase was analyzed in living cells by microinjection of regulatory and catalytic subunits labeled with fluorescein. Following microinjection, type I holoenzyme was found in the cytoplasm and remained there for up to 4 hr. Upon dissociation of holoenzyme with 8-bromo-cAMP, free catalytic subunit appeared in the nucleus while regulatory subunit remained in the cytoplasm. Similarly, purified catalytic subunit was transported to the nucleus in the absence of elevated intracellular cAMP following its introduction into the cytoplasm. Translocation to the nucleus was apparent within 10 min and persisted for at least 2 hr. In contrast, purified regulatory subunit, like holoenzyme, was maintained in the cytoplasm. These results suggest that one function of the type I regulatory subunit is to serve as a cytoplasmic anchor, sequestering the catalytic subunit in the cytoplasm until holoenzyme dissociates in response to increased cAMP.