PKCζII, a small molecule of protein kinase C ζ, specifically expressed in the mouse brain

Protein kinase C ζ (PKCζ) plays critical roles in neural development. In the brain, many PKCζ-related transcripts are expressed but they do not code the native 75 kDa PKCζ molecule. We examined the significance of such transcripts in intact cells. A PKCζ-related (PKCζII) cDNA, whose mRNA was specifically expressed in the brain, was obtained. When PKCζII cDNA was introduced to rat NRK cells using an adenovirus vector, a 50 kDa protein was detected as a truncated form of PKCζ lacking the regulatory domain. The PKCζII protein was also detected in the brain, cerebellar granule neurons and neuroblastoma cells, but not in astrocytes and glioma cells. An alternative promoter for PKCζII was localized in intron 4 of the PKCζ gene. The specificity of PKCζII expression can be regulated at the transcription level in a cell-type-specific manner.