Interrogation of MDM2 phosphorylation in p53 activation using native chemical ligation: the functional role of Ser17 phosphorylation in MDM2 reexamined.
Interrogation of MDM2 phosphorylation in p53 activation using native chemical ligation: the functional role of Ser17 phosphorylation in MDM2 reexamined.
复制标题
DOI：
10.1021/ja301255n
复制
发表时间：
2012-04-18
影响因子：
15
通讯作者：
Lu, Wuyuan
中科院分区：
文献类型：
--
作者：
Zhan, Changyou;Varney, Kristen;Yuan, Weirong;Zhao, Le;Lu, Wuyuan
The E3 ubiquitin ligase MDM2 functions as a crucial negative regulator of the p53 tumor suppressor protein by antagonizing p53 transactivation activity and targeting p53 for degradation. Cellular stress activates p53 by alleviating MDM2-mediated functional inhibition, even though the molecular mechanisms of stress-induced p53 activation still remain poorly understood. Two opposing models have been proposed to describe the functional and structural role in p53 activation of Ser17 phosphorylation in the N-terminal “lid” (residues 1–24) of MDM2. Using the native chemical ligation technique, we synthesized the p53-binding domain (1–109)MDM2 and its Ser17-phosphorylated analog (1–109)MDM2 pS17 as well as (1–109)MDM2 S17D and (25–109)MDM2, and comparatively characterized their interactions with a panel of p53-derived peptide ligands using surface plasmon resonance, fluorescence polarization, and NMR and CD spectroscopic techniques. We found that the lid is partially structured in apo-MDM2 and occludes p53 peptide binding in a ligand size-dependent manner. Binding of (1–109)MDM2 by the (15–29)p53 peptide fully displaces the lid and renders it completely disordered in the peptide-protein complex. Importantly, neither Ser17 phosphorylation nor the phospho-mimetic mutation S17D has any functional impact on p53 peptide binding to MDM2. Although Ser17 phosphorylation or its mutation to Asp contributes marginally to the stability of the lid conformation in apo-MDM2, neither modification stabilizes apo-MDM2 globally or the displaced lid locally. Our findings demonstrate that Ser17 phosphorylation is functionally neutral with respect to p53 binding, suggesting that MDM2 phosphorylation at a single site is unlikely to play a dominant role in stress-induced p53 activation.
登录
查看更多内容
影响因子：
56.9
作者：
DAWSON, PE;MUIR, TW;KENT, SBH
通讯作者：
KENT, SBH
影响因子：
4.3
作者：
Dastidar, Shubhra Ghosh;Raghunathan, Devanathan;Verma, Chandra S.
通讯作者：
Verma, Chandra S.
影响因子：
2.7
作者：
BAX A;IKURA M
通讯作者：
IKURA M
p53 抑制剂 MDM2/MDMX 复合物是控制体内 p53 活性所必需的
DOI：
10.1073/pnas.1102309108
发表时间：
2011-07-19
影响因子：
11.1
作者：
Huang, Lei;Yan, Zheng;Yuan, Zhi-Min
通讯作者：
Yuan, Zhi-Min
影响因子：
64.5
作者：
Kruse JP;Gu W
通讯作者：
Gu W