Immunocytochemical localization of protein kinase C in identified neuronal compartments of rat brain

JG Wood, PR Girard, GJ Mazzei, JF Kuo
1986 Journal of Neuroscience  
Polyclonai antisera to the phospholipidlCa2+dependent protein kinase have been used to study the distribution of the enzyme in identified neurons of several brain regions. The results indicated that the enzyme was concentrated in synaptic terminals of mossy fibers, Golgi II neurons and Purkinje neurons in the cerebellum, and in granule cell terminals in the hippocampus. These synapses have different physiological properties and utilize different neurotransmitters. Electron microscopic results
more » ... dicated that the enzyme was concentrated in presynaptic terminals. Thus, the protein kinase may play a broad role in Ca*+related events of the presynaptic terminal during neurotransmission. Light-and electron-microscopic immunocytochemical analysis also indicated that the enzyme was inside the nucleus concentrated in a region adjacent to the inner nuclear membrane, where it may play a role in the regulation of neuronal function. An interesting question in neurobiology concerns the role of phosphorylation in neuronal function. In view ofthe importance of calcium to the neuron, it is logical to focus on protein kinase systems, which are regulated in a Ca2+ -dependent manner. Two major regulator systems concerned with phosphorylation in brain (and other tissues) are the calmodulin/Ca2+ (Cheung, 1980) and the phospholipid/Ca2+-dependent proteins kinase(s) Nishizuka, 1984) . The distribution of the calmodulin/ Ca2+ system in brain has been studied using antisera to calmodulin (Wood et al., 1980) and to calmodulin kinase II (Quimet et al., 1984) . We have recently purilied phospholipid/C&+dependent protein kinase (PWCa-PK, or protein kinase C) from pig brain and raised polyclonal antibodies to the enzyme in rabbits (Girard et al., , 1986 . Our preliminary work indicated that the enzyme had a broad distribution in brain and appeared to be present both in neurons and in cells strongly resembling oligodendroglia (Girard et al., , 1986 . In this study we have performed a systematic examination of the subcellular distribution of anti-PWCa-PK immunoreactivity in identified brain regions. We show that the enzyme is concentrated in presynaptic terminals possibly in association with synaptic vesicles of a variety of neurons that utilize different neurotransmitter types. We further show that a pool of itnmunoreactivity shown by light microscopy to be in the region of the nucleus (Girard et al., , 1986 ) is inside the nucleus and is present for the most part subadjacent to the nuclear membrane. These results suggest that the PVCa-PK may also be involved in brain function at the level of regulation of nuclear function in neurons.
doi:10.1523/jneurosci.06-09-02571.1986 pmid:3746424 fatcat:gna3ifhqdnhvxbebixlf6p7dv4