De Camilli P, Ueda T, Bloom F E, Battenberg E, Greengard P
Proc Natl Acad Sci U S A. 1979 Nov;76(11):5977-81. doi: 10.1073/pnas.76.11.5977.
Protein I, a naturally occurring substrate for cyclic AMP-dependent and calcium-dependent protein kinases, previously has been found only in mammalian brain, where it has been demonstrated to be located in neurons. Various tissues and organs outside the brain have now been examined for the possible occurrence of protein I, by using both an immunohistochemical approach and a chemical procedure involving radioimmunolabeling of polyacrylamide gels. Protein I has been found in the inner plexiform layer of the retina, in the posterior pituitary, and in the autonomic nervous system. In tissue composed predominantly of cells other than nerve cells, immunoreactivity was present only where innervation was present. Protein I appeared to be localized in some, but not all, nerve terminals and synapses.
蛋白质I是一种环磷酸腺苷依赖性和钙依赖性蛋白激酶的天然底物,此前仅在哺乳动物大脑中发现,且已证实在神经元中存在。现在,通过免疫组织化学方法和涉及聚丙烯酰胺凝胶放射免疫标记的化学程序,对大脑以外的各种组织和器官进行了检测,以确定蛋白质I是否可能存在。在视网膜的内网状层、垂体后叶和自主神经系统中发现了蛋白质I。在主要由神经细胞以外的细胞组成的组织中,免疫反应仅出现在有神经支配的地方。蛋白质I似乎定位于一些但并非所有的神经末梢和突触中。