Distribution of Ca2+/calmodulin-dependent protein kinase kinase alpha in the rat central nervous system: an immunohistochemical study.

Ca2+/calmodulin-dependent protein kinase IV (CaM-kinase IV) is activated by CaM-kinase IV kinase. We provided a rabbit antiserum against 20 amino acid residues at the carboxyl-terminal end of CaM-kinase IV kinase, and examined regional and intracellular distribution of CaM-kinase IV kinase immunohistochemically in the central nervous system of the rat by light and electron microscopy. The immunoreactivity was found in cellular nuclei of virtually all neurons. However, the immunoreactivity was weak in the nuclei of the granule cells in the cerebellar cortex, although the nuclei of the granule cells were reported to contain high CaM-kinase IV activity. Thus, it was suggested that other types of CaM-kinase IV kinase might exist in the cerebellum, and the present CaM-kinase IV kinase was named as CaM-kinase kinase alpha.