A NOVEL CDC2-RELATED PROTEIN-KINASE EXPRESSED IN THE NERVOUS-SYSTEM

We report the cloning and characterization of a cDNA encoding a cdc2-r elated protein kinase, named PFTAIRE, that is expressed primarily in t he postnatal and adult nervous system. We have demonstrated by in situ hybridization and indirect immunofluorescence that several population s of terminally differentiated neurons and some neuroglia expressed PF TAIRE mRNA and protein. In neurons, PFTAIRE protein was localized in t he nucleus and cytoplasm of cell bodies. The anatomical, cellular, and ontogenic patterns of PFTAIRE expression in the nervous system differ ed from those of p34(cdc2) and cdk5, which are expressed in brain and several other mitotic tissues. Proteins of similar to 58-60 kDa coprec ipitated specifically with PFTAIRE from cytosolic protein preparations of adult mouse brain and transfected cells. These proteins appeared t o be the major endogenous substrates associated with this kinase activ ity. The temporal and spatial expression patterns of PFTAIRE in the po stnatal and adult nervous system suggest that PFTAIRE kinase activity may be associated with the postmitotic and differentiated state of cel ls in the nervous system and that its function may be distinct from th ose of p34(cdc2) and cdk5.