Distinct immunohistochemical localization of two isoforms of Ca2+/calmodulin‐dependent protein kinase kinases in the adult rat brain-猫眼课题宝

成年大鼠脑中 Ca2+/钙调蛋白依赖性蛋白激酶激酶的两种亚型的独特免疫组织化学定位

DOI：

10.1046/j.1460-9568.2000.00883.x

发表时间：

2000

期刊：

European Journal of Neuroscience

影响因子：

3.4

通讯作者：

中科院分区：

医学3区

文献类型：

作者：

H. Sakagami;M. Umemiya;S. Saito;H. Kondo

Ca 2 +/钙调蛋白依赖性蛋白激酶IV（CaM-KIV）被认为通过磷酸化各种转录因子参与调节基因表达。CaM-KIV和CaM-KI在磷酸化后被Ca 2 +/钙调蛋白依赖性蛋白激酶激酶的两种不同亚型CaM-KKs α和β激活。在这项研究中，我们提出了针对CaM-KKS的亚型特异性单克隆抗体，并与CaM-KIV相比，检查了CaM-KKS在大鼠大脑中的免疫组织化学定位。CaM-KK α-免疫反应性广泛分布于整个大脑的神经元中，小脑皮质除外。在大脑皮质、面神经核和脊髓运动神经元中观察到最高水平的CaM-KK α-免疫反应性。在海马结构、脑桥核和各种脑干核（包括三叉神经、前庭、耳蜗和舌下神经核）中观察到中度CaM-KK α-免疫反应性。相反，CaM-KK β-免疫反应性在一些神经元群体中相对受限。在小脑颗粒细胞层中观察到最高水平的CaM-KK β-免疫反应性，在大脑皮质、海马结构、尾壳核、脑桥核、耳蜗核和小脑分子层中观察到中度免疫反应性。与CaM-KIV突出的核定位相反，CaM-KKs的两种亚型均定位于核周细胞质、树突和神经末梢中，但不在细胞核中。CaM-KKs的两种亚型的不同定位表明，CaM-KKs激活CaM-KIV的复杂机制可能以区域特异性方式以及细胞内发挥作用。

Ca2+/calmodulin‐dependent protein kinase IV (CaM‐KIV) is thought to be involved in regulating gene expression by phosphorylating various transcriptional factors. CaM‐KIV as well as CaM‐KI are activated upon phosphorylation by two distinct isoforms of Ca2+/calmodulin‐dependent protein kinase kinases, CaM‐KKs α and β. In this study, we raised isoform‐specific monoclonal antibodies against CaM‐KKs and examined the immunohistochemical localization of CaM‐KKs in the rat brain, compared with that of CaM‐KIV. CaM‐KK α‐immunoreactivity was rather widely distributed in neurons throughout the brain, except cerebellar cortex. The highest levels of CaM‐KK α‐immunoreactivity were observed in the cerebral cortex, facial nucleus and motor neurons of the spinal cord. Moderate CaM‐KK α‐immunoreactivity was observed in the hippocampal formation, pontine nuclei and various brain stem nuclei including trigeminal, vestibular, cochlear and hypoglossal nuclei. In contrast, CaM‐KK β‐immunoreactivity was relatively restricted in some neuronal populations. The highest levels of CaM‐KK β‐immunoreactivity were observed in the cerebellar granule cell layer, and moderate immunoreactivity was observed in the cerebral cortex, hippocampal formation, caudate putamen, pontine nuclei, cochlear nucleus and molecular layer of the cerebellum. In contrast to the prominent nuclear localization of CaM‐KIV, both isoforms of CaM‐KKs were localized in the perikaryal cytoplasm, dendrites and nerve terminals, but not in the cell nuclei. The distinct localization of two isoforms of CaM‐KKs suggests that the complicated mechanisms for activation of CaM‐KIV by CaM‐KKs may be exerted in region‐specific manners as well as intracellularly.