Localization of the cellular expression pattern of cdc25NEF and ras in the juvenile rat brain.

In this report, we demonstrate that the brain-specific ras nucleotide-exchange factor, cdc25NEF-B, is expressed in specific neuronal populations in the juvenile rat brain. Because cdc25NEF-B likely regulates one or more of the vertebrate ras proteins, H-, K- and N-ras, we also examined their levels of expression and pattern of expression in the juvenile rat brain. We find cdc25NEF-B to be highly expressed in the hippocampus, some deep nuclei, neocortex, and the granule cell layer of the anterior lobules of the cerebellum. Our observations suggest a functional link between cdc25NEF-B and H-ras in a neuronal signal transduction pathway.