Cooper N G, Wei X, Liu N
Department of Anatomical Sciences and Neurobiology, University of Louisville School of Medicine, KY, USA.
J Mol Neurosci. 1995;6(2):75-89. doi: 10.1007/BF02736768.
Calcium-calmodulin-dependent protein kinase II is an abundant protein in the nervous system and has been associated with many aspects of neuronal function, including events related to synaptic transmission. The purpose of this study is to correlate the onset of expression of this kinase with a specific developmental event in retinal morphogenesis using a monoclonal antibody to the 50-kDa alpha-subunit. Microscopy showed the antigen to be associated with the plexiform layers of the retina. Western blots demonstrated that the onset of expression of the alpha-subunit coincided in time with the initial formation of the plexiform layers. However, the onset of expression of the 50-kDa alpha-subunit was preceded by the earlier embryonic appearance of a related 82.5-kDa antigen that was recognized by the antibody. The amount of this latter protein declined as the amount of the alpha-subunit increased in retinal homogenates. Although this related 82.5 kDa protein disappeared from blots of retinal homogenates after embryonic d 14, it could be detected in concentrated supernatant fractions isolated from the retinae of hatched chicks. Microscopy showed that a subset of retinal cells and their processes contained this antigen in early embryonic chicks. Finally, the 50 kDa alpha-subunit of kinase II and the 82.5 kDa novel antigen were shown to be separable by differential centrifugation.
钙调蛋白依赖性蛋白激酶II是神经系统中一种丰富的蛋白质，与神经元功能的许多方面有关，包括与突触传递相关的事件。本研究的目的是使用针对50 kDaα亚基的单克隆抗体，将这种激酶的表达起始与视网膜形态发生中的特定发育事件相关联。显微镜检查显示该抗原与视网膜的神经丛层相关。蛋白质印迹法表明，α亚基的表达起始与神经丛层的最初形成在时间上一致。然而，50 kDaα亚基的表达起始之前，抗体识别出一种相关的82.5 kDa抗原在胚胎期更早出现。在视网膜匀浆中，随着α亚基数量的增加，后一种蛋白质的数量下降。尽管这种相关的82.5 kDa蛋白质在胚胎第14天之后从视网膜匀浆的印迹中消失，但在从孵化雏鸡视网膜中分离的浓缩上清液组分中可以检测到。显微镜检查显示，在早期胚胎雏鸡中，一部分视网膜细胞及其突起含有这种抗原。最后，通过差速离心显示激酶II的50 kDaα亚基和82.5 kDa新抗原是可分离的。
