Characterization of the interaction between DARPP-32 and protein phosphatase 1 (PP-1): DARPP-32 peptides antagonize the interaction of PP-1 with binding proteins
Characterization of the interaction between DARPP-32 and protein phosphatase 1 (PP-1): DARPP-32 peptides antagonize the interaction of PP-1 with binding proteins
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DOI：
10.1073/pnas.94.8.3536
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发表时间：
1997-04-15
影响因子：
11.1
通讯作者：
Nairn, AC
中科院分区：
文献类型：
--
作者：
Kwon, YG;Huang, HB;Nairn, AC
PP-1 (PP-1C) 的催化亚基被 DARPP-32（(d) 在 bar opamine- 下，c (A) 在 bar MP-(r) 在 bar 调节下 (p) 在 bar hos (p) 在 bar ho Protein，M-r,000 下）、inhibitor-1 和抑制剂-2 有效抑制（IC50，大约 1 nM）。 DARPP-32 和抑制剂-1 的 NH2 末端 50 个氨基酸残基相似，并且共同的苏氨酸残基 (Thr-34/Thr-35) 的磷酸化对于抑制 PP-1C 是必需的。我们进一步表征了 DARPP-32 和 PP-1C 之间的相互作用。使用衍生自 DARPP-32 NH2 末端区域的合成肽，残基 6-11，RKKIQF，已被证明是抑制 PP-1C 所必需的。含有该基序的肽能够拮抗磷酸-DARPP-32 和磷酸抑制剂-1 对 PP-1C 的抑制。这些拮抗剂肽也减弱了抑制剂 2 对 PP-1C 的抑制作用，但大田酸、微囊藻毒素或花萼蛋白 A 没有抑制作用。这些结果与其他研究的结果一起支持了磷酸-DARPP-32 的两个子结构域与 PP-1C 相互作用的模型。包含磷酸化 Thr-34 的区域似乎与酶的活性位点相互作用，从而阻断酶活性。包含 RKKIQF 基序的区域与从活性位点移除的 PP-1C 结构域结合。氨基酸序列分析表明，RKKIQF 基序的基本和疏水特征在某些 PP-1C 靶向蛋白的结合域中是保守的，这表明抑制剂蛋白和靶向蛋白的相互作用可能是相互排斥的。
The catalytic subunit of PP-1 (PP-1C) is potently inhibited (IC50, approximate to 1 nM) by DARPP-32 ((d) under bar opamine- and c (A) under bar MP-(r) under bar egulated (p) under bar hos (p) under bar hoprotein, M-r,000), inhibitor-1, and inhibitor-2. The NH2-terminal 50 amino acid residues of DARPP-32 and inhibitor-1 are similar, and phosphorylation of a common threonine residue (Thr-34/Thr-35) is necessary for inhibition of PP-1C. We have characterized further the interaction between DARPP-32 and PP-1C. Using synthetic peptides derived from the NH2-terminal region of DARPP-32, residues 6-11, RKKIQF, have been shown to be required for inhibition of PP-1C. Peptides containing this motif were able to antagonize the inhibition of PP-1C by phospho-DARPP-32 and phosphoinhibitor-1. The inhibition of PP-1C by inhibitor-2, but not by okadaic acid, microcystin, or calyculin A, was also attentuated by these antagonist peptides. These results together with results from other studies support a model in which two subdomains of phospho-DARPP-32 interact with PP-1C. The region encompassing phospho-Thr-34 appears to interact with the active site of the enzyme blocking enzyme activity. The region encompassing the RKKIQF motif binds to a domain of PP-1C removed from the active site. Amino acid sequence analysis indicates that basic and hydrophobic features of the RKKIQF motif are conserved in the binding domains of certain PP-1C targeting proteins, suggesting that interaction of inhibitor proteins and targeting proteins may be mutually exclusive.