Precursor of cdk5 activator, the 23 kDa subunit of tau protein kinase II: its sequence and developmental change in brain.
Tau protein kinase II (TPKII) is shown by immunoprecipitation to be a complex composed of two subunits, a catalytic subunit, cdk5, and regulatory subunit, p23. By sequence analysis of p23 cDNA, p23 was found to occupy a region from the 99th amino acid residue to the C-terminus of a novel protein with a molecular weight of 34,000 Da, suggesting that this 34 kDa protein is a precursor of p23 (pre-p23). These findings suggest that p23 results from the processing of the precursor protein, pre-p23. The precursor mRNA was expressed most abundantly in rat brain just before and after birth. Expression of pre-p23, but not of cdk5, mRNA changed, coinciding with the developmental change of TPKII activity, suggesting that its expression controls the phosphorylation of tau by the TPKII/TPKI system in the neonatal brain. p23 appears to be a cdk5 activator in neuronal cells.
Mitsubishi Kasei Institute of Life Sciences, Tokyo, Japan.
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Uchida
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Ishiguro
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Ohnuma
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Takamatsu
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Yonekura
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Imahori
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D001921:Brain / Q000254:growth & development / Q000378:metabolism*; D002417:Cattle; D003062:Codon; D051360:Cyclin-Dependent Kinase 5; D018844:Cyclin-Dependent Kinases; D015870:Gene Expression; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010766:Phosphorylation; D011498:Protein Precursors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017422:Sequence Analysis, DNA
C090520:CDK5R1 protein, Bos taurus; D003062:Codon; D011498:Protein Precursors; D051360:Cyclin-Dependent Kinase 5; D017346:Protein Serine-Threonine Kinases; C495907:Cdk5 protein, rat; D018844:Cyclin-Dependent Kinases; C079134:tau protein kinase II