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The Highly Recurrent PP2A A?-Subunit Mutation P179R Alters Protein Structure and Impairs PP2A Enzyme Function to Promote Endometrial Tumorigenesis.

ABSTRACT: Somatic mutation of the protein phosphatase 2A (PP2A) A?-subunit gene PPP2R1A is highly prevalent in high-grade endometrial carcinoma. The structural, molecular, and biological basis by which the most recurrent endometrial carcinoma-specific mutation site P179 facilitates features of endometrial carcinoma malignancy has yet to be fully determined. Here, we used a series of structural, biochemical, and biological approaches to investigate the impact of the P179R missense mutation on PP2A function. Enhanced sampling molecular dynamics simulations showed that arginine-to-proline substitution at the P179 residue changes the protein's stable conformation profile. A crystal structure of the tumor-derived PP2A mutant revealed marked changes in A-subunit conformation. Binding to the PP2A catalytic subunit was significantly impaired, disrupting holoenzyme formation and enzymatic activity. Cancer cells were dependent on PP2A disruption for sustained tumorigenic potential, and restoration of wild-type A? in a patient-derived P179R-mutant cell line restored enzyme function and significantly attenuated tumorigenesis and metastasis in vivo. Furthermore, small molecule-mediated therapeutic reactivation of PP2A significantly inhibited tumorigenicity in vivo. These outcomes implicate PP2A functional inactivation as a critical component of high-grade endometrial carcinoma disease pathogenesis. Moreover, they highlight PP2A reactivation as a potential therapeutic strategy for patients who harbor P179R PPP2R1A mutations. SIGNIFICANCE: This study characterizes a highly recurrent, disease-specific PP2A PPP2R1A mutation as a driver of endometrial carcinoma and a target for novel therapeutic development.See related commentary by Haines and Huang, p. 4009.

SUBMITTER: Taylor SE

PROVIDER: S-EPMC6724736 | biostudies-literature | 2019 Aug

REPOSITORIES: biostudies-literature

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The Highly Recurrent PP2A Aα-Subunit Mutation P179R Alters Protein Structure and Impairs PP2A Enzyme Function to Promote Endometrial Tumorigenesis.

Taylor Sarah E SE O'Connor Caitlin M CM Wang Zhizhi Z Shen Guobo G Song Haichi H Leonard Daniel D Sangodkar Jaya J LaVasseur Corinne C Avril Stefanie S Waggoner Steven S Zanotti Kristine K Armstrong Amy J AJ Nagel Christa C Resnick Kimberly K Singh Sareena S Jackson Mark W MW Xu Wenqing W Haider Shozeb S DiFeo Analisa A Narla Goutham G

Cancer research 20190529 16

Somatic mutation of the protein phosphatase 2A (PP2A) Aα-subunit gene <i>PPP2R1A</i> is highly prevalent in high-grade endometrial carcinoma. The structural, molecular, and biological basis by which the most recurrent endometrial carcinoma-specific mutation site P179 facilitates features of endometrial carcinoma malignancy has yet to be fully determined. Here, we used a series of structural, biochemical, and biological approaches to investigate the impact of the P179R missense mutation on PP2A f ...[more]

PMID: 31142515

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Dataset Information

The Highly Recurrent PP2A A?-Subunit Mutation P179R Alters Protein Structure and Impairs PP2A Enzyme Function to Promote Endometrial Tumorigenesis.

Publications

The Highly Recurrent PP2A Aα-Subunit Mutation P179R Alters Protein Structure and Impairs PP2A Enzyme Function to Promote Endometrial Tumorigenesis.

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