Biernat J, Mandelkow E M, Schröter C, Lichtenberg-Kraag B, Steiner B, Berling B, Meyer H, Mercken M, Vandermeeren A, Goedert M, Mandelkow E
Max-Planck-Unit for Structural Molecular Biology, Hamburg, FRG.
EMBO J. 1992 Apr;11(4):1593-7. doi: 10.1002/j.1460-2075.1992.tb05204.x.
The paired helical filaments (PHFs) of Alzheimer's disease consist mainly of the microtubule-associated protein tau. PHF tau differs from normal human brain tau in that it has a higher Mr and a special state of phosphorylation. However, the protein kinase(s) involved, the phosphorylation sites on tau and the resulting conformational changes are only poorly understood. Here we show that a new monoclonal antibody, AT8, records the PHF-like state of tau in vitro, and we describe a kinase activity that turns normal tau into a PHF-like state. The epitope of AT8 is around residue 200, outside the region of internal repeats and requires the phosphorylation of serines 199 and/or 202. Both of these are followed by a proline, suggesting that the kinase activity belongs to the family of proline-directed kinases. The epitope of AT8 is nearly coincident with that of another phosphorylation-dependent antibody, TAU1 [Binder, L.I., Frankfurter, A. and Rebhun, L. (1985) J. Cell Biol., 101, 1371-1378], but the two are complementary since TAU1 requires a dephosphorylated epitope.
阿尔茨海默病的双螺旋丝（PHFs）主要由微管相关蛋白tau组成。PHF tau与正常人类脑tau的不同之处在于它具有更高的分子量和特殊的磷酸化状态。然而，所涉及的蛋白激酶、tau上的磷酸化位点以及由此产生的构象变化目前仍知之甚少。在此，我们表明一种新的单克隆抗体AT8能在体外记录tau的PHF样状态，并且我们描述了一种能将正常tau转变为PHF样状态的激酶活性。AT8的表位在第200位残基附近，位于内部重复区域之外，并且需要丝氨酸199和/或202的磷酸化。这两个丝氨酸后面都跟着一个脯氨酸，这表明该激酶活性属于脯氨酸定向激酶家族。AT8的表位与另一种磷酸化依赖性抗体TAU1的表位几乎重合[Binder, L.I., Frankfurter, A.和Rebhun, L. (1985) J. Cell Biol., 101, 1371 - 1378]，但两者是互补的，因为TAU1需要一个去磷酸化的表位。
