Shimohama S, Saitoh T, Gage F H
Department of Neurosciences, School of Medicine (M-024), University of California, San Diego, La Jolla 92093.
J Chem Neuroanat. 1990 Sep-Oct;3(5):367-75.
Protein kinase C (PKC) is a family of enzymes found throughout the body, with the greatest diversity and concentration in brain tissue. To understand further the differential role of PKC isozymes in brain, we have raised antibodies against four PKC isoforms--alpha, beta I, beta II and gamma--using specific amino acid sequences predicted from cDNA sequences. On Western blot of rat cerebellar homogenate, these antibodies stained a band of Mr 80,000, a known molecular mass for PKC, except for anti-PKC(beta II), which stained an additional minor Mr 90,000 band. On rat cerebellar sections, specific sets of cells were stained by each antibody. In the molecular layer, stellate and basket cells were stained with anti-PKC(alpha) but not with anti-PKC(beta I), -(beta II), or -(gamma). Anti-PKC (alpha) and anti-PKC(beta II) seemed to stain the Bergmann glial fibre. In the Purkinje cell layer, Purkinje cells were stained with anti-PKC[beta I) and -(gamma). Anti-PKC (alpha) and -(beta II) were negative. Interestingly, a few Purkinje cells were not stained with anti-PKC(gamma). In the granule cell layer, both granule and Golgi cells were stained with anti-PKC(beta I) and -(beta II) but not with anti-PKC(alpha) or -(gamma). Glial cells were stained with anti-PKC(beta II) but not with anti-PKC(alpha), -(beta I), or -(gamma). This study suggests a differential distribution of PKC isoforms in different cells, irrespective of their neurotransmitters. The presence of both positive and negative staining of Purkinje cells with anti-PKC(gamma) raised the possibility of their heterogeneity.
蛋白激酶C（PKC）是一类遍布全身的酶家族，在脑组织中的种类最多、浓度最高。为了进一步了解PKC同工酶在大脑中的不同作用，我们利用从cDNA序列预测的特定氨基酸序列，制备了针对四种PKC同工型——α、βI、βII和γ——的抗体。在大鼠小脑匀浆的蛋白质印迹法中，除了抗PKC（βII）染出一条额外的90,000道尔顿的次要条带外，这些抗体均染出一条80,000道尔顿的条带，这是PKC已知的分子量。在大鼠小脑切片上，每种抗体都能对特定的细胞群进行染色。在分子层，星状细胞和篮状细胞被抗PKC（α）染色，但未被抗PKC（βI）、抗PKC（βII）或抗PKC（γ）染色。抗PKC（α）和抗PKC（βII）似乎能染出伯格曼胶质纤维。在浦肯野细胞层，浦肯野细胞被抗PKC（βI）和抗PKC（γ）染色。抗PKC（α）和抗PKC（βII）呈阴性。有趣的是，一些浦肯野细胞未被抗PKC（γ）染色。在颗粒细胞层，颗粒细胞和高尔基细胞都被抗PKC（βI）和抗PKC（βII）染色，但未被抗PKC（α）或抗PKC（γ）染色。胶质细胞被抗PKC（βII）染色，但未被抗PKC（α）、抗PKC（βI）或抗PKC（γ）染色。这项研究表明，PKC同工型在不同细胞中存在差异分布，与它们的神经递质无关。浦肯野细胞对抗PKC（γ）呈现阳性和阴性染色，这增加了它们存在异质性的可能性。
