Proline-directed and Non-proline-directed Phosphorylation of PHF-tau

作者：Maho Morishima‐Kawashima, Masato Hasegawa, Koji Takio, Masami Suzuki, Hirotaka Yoshida, Koiti Titani, Yasuo Ihara · 发表于：Journal of Biological Chemistry · 年份：1995 · DOI：10.1074/jbc.270.2.823 · 被引用次数：562 · 研究领域：Advanced Proteomics Techniques and Applications、Bone health and treatments、Protease and Inhibitor Mechanisms

To gain insight into the abnormal phosphorylation of PHF-tau, we have determined the phosphorylation sites by identifying phosphopeptides by means of ion spray mass spectrometry followed by sequencing of ethane-thiol-modified peptides. Nineteen sites have been identified; all but Ser-262 are localized to the amino- and carboxyl-terminal flanking regions of the microtubule-binding domain. Eleven sites correspond to fetal type sites. Unexpectedly, 10 are non-proline-directed, whereas the others are proline-directed. Thus, the abnormal phosphorylation of PHF-tau can be considered to consist of fetal type phosphorylation and additional proline-directed and non-proline-directed phosphorylation. This non-fetal type phosphorylation may provide PHF-tau with the unusual characteristics.