Lan protein is phosphorylated by cyclic AMP-dependent protein kinase and calcium/calmodulin-dependent protein kinase II within its microtubule-binding domains at Ser-262 and Ser-356
Lan protein is phosphorylated by cyclic AMP-dependent protein kinase and calcium/calmodulin-dependent protein kinase II within its microtubule-binding domains at Ser-262 and Ser-356
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DOI：
10.1042/bj3160655
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发表时间：
1996-06-01
影响因子：
4.1
通讯作者：
Seubert, P
中科院分区：
文献类型：
--
作者：
Litersky, JM;Johnson, GVW;Seubert, P
tau蛋白在Ser-262的磷酸化已经显示出降低其与紫杉醇稳定的微管结合的能力。在阿尔茨海默病脑中发现的成对螺旋丝（PHF）由PHF-tau组成，其在包括Ser-262的多个位点处过度磷酸化。然而，能够磷酸化该位点的蛋白激酶仍在研究中。在这项研究中，环AMP依赖性蛋白激酶（cAMP-PK）和钙/钙调蛋白依赖性蛋白激酶II（CaMKII）在Ser-262以及Ser-356磷酸化tau的能力通过使用单克隆抗体（12 E8）来证明，该单克隆抗体已被证明在这些位点被磷酸化时识别tau。通过2-硝基-5-硫氰基苯甲酸在半胱氨酸残基处切割cAMP-PK-磷酸化tau，将蛋白质切割成基本上两个片段并将Ser-262与Ser-356分离，揭示了cAMP-PK使Ser-262和Ser-356磷酸化。此外，其中Ser-262、Ser-356或两者都已突变为丙氨酸的重组tau的cAMP-PK或CaMK II磷酸化清楚地证明cAMP-PK和CaMK II能够磷酸化两个位点。丝裂原活化蛋白激酶或蛋白激酶C不磷酸化tau的Ser-262和/或Ser-356。最后，有证据表明，这两个网站的磷酸化发生在培养的神经细胞在一定条件下，表明其潜在的生理相关性。
Phosphorylation of tau protein at Ser-262 has been shown to diminish its ability to bind to taxol-stabilized microtubules. The paired helical filaments (PHFs) found in Alzheimer's disease brain are composed of PHF-tau, which is hyperphosphorylated at multiple sites including Ser-262. However, protein kinase(s) able to phosphorylate this site are still under investigation. In this study, the ability of cyclic AMP-dependent protein kinase (cAMP-PK) and calcium/calmodulin-dependent protein kinase II (CaMKII) to phosphorylate tau at Ser-262, as well as Ser-356, is demonstrated by use of a monoclonal antibody (12E8) which has been shown to recognize tau when these sites are phosphorylated. Cleavage of cAMP-PK-phosphorylated tau at cysteine residues by 2-nitro-5-thiocyanobenzoic acid, which cuts the protein into essentially two fragments and separates Ser-262 from Ser-356, revealed that cAMP-PK phosphorylates both Ser-262 and Ser-356. In addition, phosphorylation with cAMP-PK or CaMKII of recombinant tau in which Ser-262, Ser-356 or both had been mutated to alanines, clearly demonstrated that cAMP-PK and CaMKII were able to phosphorylate both sites. Mitogen-activated protein kinase or protein kinase C did not phosphorylate tau at Ser-262 and/or Ser-356. Finally, evidence is presented that phosphorylation of both these sites occurs in cultured nerve cells under certain conditions, indicating their potential physiological relevance.