Distribution and intracellular localization of a mouse homologue of Ca2+/calmodulin-dependent protein kinase I beta 2 in the nervous system

Ca2+/calmodulin-dependent protein kinases (CaMKs) are believed to play impo rtant roles in the development and function of the nervous system. We repor t here the identification and expression of mouse CaMKI beta (mCaMKl beta), in particular mCaMKl beta 2, an isoform of mCaMKl beta. During embryogenes is, the mCaMKI beta 2 gene is expressed mainly in the nervous system, inclu ding brain, spinal cord, trigeminal ganglion, and retina. Within the CNS, t he expression of mCaMKIb2 is detected in the mantle zone, but not in the ve ntricular zone, suggesting its possible involvement in the differentiation of neurons. In the adult brain, mCaMKI beta 2 transcripts are detected at h igh levels in the anterior olfactory nuclei, piriform cortex, septal nuclei , bed nuclei of the stria terminalis, hippocampal pyramidal cells, dentate granule cells, amygdala, hypothalamic nuclei, parabrachial nucleus, and nuc leus of the solitary tract. The distinct gene expression pattern suggests t hat mCaMKI beta 2 may also be involved in different mature neuronal functio ns from other CaMKs. In addition, mCaMKl beta 2 proteins are localized to t he cytoplasm and nuclei, but not to nucleoli, suggesting that mCaMKI beta 2 proteins might be involved in the cytoplasmic and nuclear signal transduct ion of the nervous system.