Phosphorylation-mediated PTEN conformational closure and deactivation revealed with protein semisynthesis

被引：77

作者：

Bolduc, David ^{[1
]}

Rahdar, Meghdad ^{[2
]}

Tu-Sekine, Becky ^{[3
]}

Sivakumaren, Sindhu Carmen ^{[1
]}

Raben, Daniel ^{[3
]}

Amzel, L. Mario ^{[4
]}

Devreotes, Peter ^{[5
]}

Gabelli, Sandra B. ^{[4
,6
]}

Cole, Philip ^{[1
]}

机构：

[1] Johns Hopkins Univ, Sch Med, Dept Pharmacol & Mol Sci, Baltimore, MD 21205 USA

[2] Univ Calif San Diego, Dept Pharmacol, San Diego, CA 92103 USA

[3] Johns Hopkins Univ, Sch Med, Dept Biol Chem, Baltimore, MD 21205 USA

[4] Johns Hopkins Univ, Sch Med, Dept Biophys & Biophys Chem, Baltimore, MD 21218 USA

[5] Johns Hopkins Univ, Sch Med, Dept Cell Biol, Baltimore, MD USA

[6] Johns Hopkins Univ, Sch Med, Dept Med Oncol, Baltimore, MD USA

来源：

ELIFE | 2013年 / 2卷

基金：

美国国家卫生研究院;

关键词：

TUMOR-SUPPRESSOR PTEN; PHOSPHATASE-ACTIVITY; CRYSTAL-STRUCTURE; TYROSINE PHOSPHORYLATION; KINETIC-ANALYSIS; ACTIVATION; GENE; PTEN/MMAC1; SCATTERING; BINDING;

D O I：

10.7554/eLife.00691

中图分类号：

Q [生物科学];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

The tumor suppressor PIP3 phosphatase PTEN is phosphorylated on four clustered Ser/Thr on its C-terminal tail (aa 380-385) and these phosphorylations are proposed to induce a reduction in PTEN's plasma membrane recruitment. How these phosphorylations affect the structure and enzymatic function of PTEN is poorly understood. To gain insight into the mechanistic basis of PTEN regulation by phosphorylation, we generated semisynthetic site-specifically tetra-phosphorylated PTEN using expressed protein ligation. By employing a combination of biophysical and enzymatic approaches, we have found that purified tail-phosphorylated PTEN relative to its unphosphorylated counterpart shows reduced catalytic activity and membrane affinity and undergoes conformational compaction likely involving an intramolecular interaction between its C-tail and the C2 domain. Our results suggest that there is a competition between membrane phospholipids and PTEN phospho-tail for binding to the C2 domain. These findings reveal a key aspect of PTEN's regulation and suggest pharmacologic approaches for direct PTEN activation.

引用

页数：19