Dephosphorylation of autophosphorylated Ca2+/calmodulin-dependent protein kinase II by protein phosphatase 2C.
Dephosphorylation of autophosphorylated Ca2+/calmodulin-dependent protein kinase II by protein phosphatase 2C.
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DOI：
10.1016/s0021-9258(18)54124-7
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发表时间：
1993-01
期刊：
影响因子：
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通讯作者：
Kohji Fukunaga;Takayasu Kobayashi;S. Tamura;E. Miyamoto
中科院分区：
文献类型：
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作者：
Kohji Fukunaga;Takayasu Kobayashi;S. Tamura;E. Miyamoto
已经证明，大田酸不敏感蛋白磷酸酶参与大鼠小脑颗粒细胞中自磷酸化 Ca2+/钙调蛋白依赖性蛋白激酶 II (CaM 激酶 II) 的去磷酸化(Fukunaga, K., Rich, D. P., and Soderling, T. R. (1989) J. Biol. Chem. 264, 21830-21836)。在本研究中，在大肠杆菌中表达的重组大鼠蛋白磷酸酶2C（PrP-2C）可以使CaM激酶II的Thr286/287和Thr305/306磷酸化位点去磷酸化，这两个位点分别负责Ca(2+)独立活性的产生和总活性的抑制。 Thr286/287 和 Thr305/306 的去磷酸化在 0 摄氏度下 15 分钟内完成，完全依赖于 Mg2+。 CNBr 切割的 32P 标记的 CaM 激酶 II 的磷酸肽作图表明，PrP-2C 对于自磷酸化 CaM 激酶 II 中的 Thr286/287 和 Thr305/306 去磷酸化具有相对特异性。这些结果表明PrP-2C 在调节神经细胞中CaM 激酶II 的Ca(2+) 独立活性中发挥作用。
It has been demonstrated that okadaic acid-insensitive protein phosphatases are involved in dephosphorylation of autophosphorylated Ca2+/calmodulin-dependent protein kinase II (CaM kinase II) in rat cerebellar granule cells (Fukunaga, K., Rich, D. P., and Soderling, T. R. (1989) J. Biol. Chem. 264, 21830-21836). In the present study, recombinant rat protein phosphatase 2C (PrP-2C) expressed in Escherichia coli could dephosphorylate both Thr286/287 and Thr305/306 phosphorylation sites of CaM kinase II, which are responsible for the generation of Ca(2+)-independent activity and the inhibition of the total activity, respectively. The dephosphorylation of Thr286/287 and Thr305/306 was accomplished within 15 min at 0 degrees C and totally dependent on Mg2+. Phosphopeptide mapping of the CNBr-cleaved 32P-labeled CaM kinase II revealed that PrP-2C was relatively specific for dephosphorylation of Thr286/287 and Thr305/306 in the autophosphorylated CaM kinase II. These results suggest that PrP-2C has a role in the regulation of the Ca(2+)-independent activity of CaM kinase II in the neural cells.