PCTAIRE 2, a Cdc2-related serine/threonine kinase, is predominantly expressed in terminally differentiated neurons.
PCTAIRE are members of a subfamily of Cdc2-related kinases that have been shown to be preferentially expressed in post-mitotic cells. To examine the neural functions of PCTAIRE, rat cDNA clones encoding PCTAIRE 1, 2, and 3 were isolated, and their expression patterns in the brain were analyzed. Among the three rat PCTAIREs, only PCTAIRE 2 was found to be specifically expressed in the brain. Furthermore, its expression was transiently increased during brain development, peaking 7-15 days after birth. Within the brain, PCTAIRE 2 was concentrated in the neuronal layers of the hippocampus and olfactory bulb, which mostly consist of post-mitotic neurons. In an immunocytochemical experiment, immunoreactivity for PCTAIRE 2 was detected in the cell bodies and extended neurites of neurons, but not in astrocytes. The PCTAIRE 2 protein was recovered in the particulate fraction and resistant to solubilization with non-ionic detergent, suggesting that PCTAIRE 2 might be present as a component of a large protein complex. An immunoprecipitation assay revealed that the PCTAIRE 2 was associated with Ser/Thr-phosphorylating activity for histone H1, and that its activity depended on association with a regulatory partner that can be released under high-salt conditions. These findings suggest that PCTAIRE 2 is a Ser/Thr kinase that might play a unique role in terminally differentiated neurons.
Hirose
T
T
Division of Protein Metabolism, Institute for Protein Research, Osaka University, Suita, Japan. hirose@protein.osaka-u.ac.jp
Tamaru
T
T
Okumura
N
N
Nagai
K
K
Okada
M
M
D000375:Aging / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000196:embryology / Q000201:enzymology* / Q000254:growth & development; D002453:Cell Cycle; D002454:Cell Differentiation; D002478:Cells, Cultured; D003001:Cloning, Molecular; D018844:Cyclin-Dependent Kinases; D005314:Embryonic and Fetal Development; D018507:Gene Expression Regulation, Developmental; D015971:Gene Expression Regulation, Enzymologic; D015723:Gene Library; D006624:Hippocampus / Q000166:cytology / Q000201:enzymology; D006801:Humans; D007031:Hypothalamus / Q000201:enzymology; D008969:Molecular Sequence Data; D009474:Neurons / Q000166:cytology / Q000201:enzymology*; D009830:Olfactory Bulb / Q000166:cytology / Q000201:enzymology; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis* / Q000737:chemistry; D051381:Rats; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D011994:Recombinant Proteins; D017346:Protein Serine-Threonine Kinases; D018844:Cyclin-Dependent Kinases; C089463:PCTAIRE-1 protein kinase; C109207:PCTAIRE-2 protein kinase; C089464:PCTAIRE-3 protein kinase