Medina M, Montejo de Garcini E, Avila J
Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), Madrid, Spain.
Mol Cell Biochem. 1995 Jul 5;148(1):79-88. doi: 10.1007/BF00929506.
Tau cDNAs from each of the six human isoforms were transfected into COS-1 cells and, in every case, more than one peptide was observed. The diversity of expressed isoforms was due to different levels of tau phosphorylation. Tau phosphorylation results in a decrease of the protein electrophoretic mobility. The major contribution to this mobility shift is due to the phosphorylation at the at the C-terminus of the molecule, as inferred from the expression of tau fragments. Phosphorylation takes place in some of the sites modified in neural cells and in the basis of AD patients. Copolymerization studies indicate that the level of phosphorylation, as well as the localization of the modified residues, may affect the binding of the protein to microtubules. These results indicate that phosphorylation regulates tau function inside the cell.
来自六种人类异构体的tau cDNA被转染到COS-1细胞中，并且在每种情况下，都观察到了不止一种肽。所表达异构体的多样性是由于tau磷酸化水平不同。tau磷酸化导致蛋白质电泳迁移率降低。从tau片段的表达推断，这种迁移率变化的主要原因是分子C末端的磷酸化。磷酸化发生在神经细胞和阿尔茨海默病患者大脑中一些被修饰的位点上。共聚研究表明，磷酸化水平以及修饰残基的定位可能会影响蛋白质与微管的结合。这些结果表明，磷酸化在细胞内调节tau的功能。
