Dreyfuss G, Schwartz K J, Blout E R
Proc Natl Acad Sci U S A. 1978 Dec;75(12):5926-30. doi: 10.1073/pnas.75.12.5926.
The human erythrocyte contains two types of cyclic AMP-dependent protein kinase. The membrane-associated protein kinase holoenzyme can be released intact by hypotonic treatment at alkaline pH. Chromatography on DEAE-cellulose and molecular weight determinations demonstrate that this enzyme is a type I cyclic AMP-dependent protein kinase, while the predominant cyclic AMP-dependent protein kinase found in the cytoplasm is type II. The catalytic subunits of the two types of kinase found in the erythrocyte are identical, but the regulatory subunits, which distinguish the two types of kinase, determine their localization within the cell. It is proposed that the regulatory subunit of the type I enzyme, in addition to binding the catalytic subunit, interacts specifically with one or more membrane proteins and that this interaction may serve to position the kinase in preferential proximity to protein substrates.
人类红细胞含有两种环磷酸腺苷（cAMP）依赖性蛋白激酶。膜相关蛋白激酶全酶在碱性pH下经低渗处理可完整释放。通过DEAE - 纤维素色谱法和分子量测定表明，这种酶是I型cAMP依赖性蛋白激酶，而在细胞质中发现的主要的cAMP依赖性蛋白激酶是II型。红细胞中发现的两种激酶的催化亚基是相同的，但区分这两种激酶的调节亚基决定了它们在细胞内的定位。有人提出，I型酶的调节亚基除了与催化亚基结合外，还与一种或多种膜蛋白特异性相互作用，这种相互作用可能有助于将激酶定位在优先靠近蛋白质底物的位置。
