Tau protein kinase I converts normal tau protein into A68-like component of paired helical filaments.
From bovine brain microtubules we purified tau protein kinase I (TPKI, Mr 45,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and tau protein kinase II (TPKII) whose activity was attributed to a 30-kDa protein on SDS-PAGE by affinity-labeling using an ATP analog. Both kinases were activated by tubulin. TPKII, but not TPKI, phosphorylated tau fragment peptides previously used for detection of a Ser/ThrPro kinase activity. Therefore, TPKII was considered to be the Ser/ThrPro kinase. TPKI was more effective than TPKII for producing the decrease of tau-1 immunoreactivity and mobility shift of tau on SDS-PAGE. Moreover, TPKI, but not TPKII nor other well-known protein kinases, generated an epitope present on paired helical filaments. These findings suggested that tau phosphorylated by TPKI resembled A-68, a component of paired helical filaments.
Ishiguro
K
K
Mitsubishi Kasei Institute of Life Sciences, Tokyo, Japan.
Takamatsu
M
M
Tomizawa
K
K
Omori
A
A
Takahashi
M
M
Arioka
M
M
Uchida
T
T
Imahori
K
K
D000345:Affinity Labels; D000818:Animals; D001921:Brain / Q000201:enzymology; D002417:Cattle; D002853:Chromatography, Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D009419:Nerve Tissue Proteins / Q000378:metabolism*; D016874:Neurofibrillary Tangles / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism; D010766:Phosphorylation; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D013379:Substrate Specificity; D016875:tau Proteins / Q000378:metabolism*
D000345:Affinity Labels; C054369:MAPT protein, human; D009419:Nerve Tissue Proteins; D010446:Peptide Fragments; D016875:tau Proteins; D011494:Protein Kinases