Methylation-regulated decommissioning of multimeric PP2A complexes. Issue 1 (December 2017)

• Record Type: Journal Article
• Authors: Wu, Cheng-Guo; Zheng, Aiping; Jiang, Li; Rowse, Michael; Stanevich, Vitali; Chen, Hui; Li, Yitong; Satyshur, Kenneth; Johnson, Benjamin; Gu, Ting-Jia; Liu, Zuojia; Xing, Yongna
• Is Part Of: Nature communications. Volume 8:Issue 1(2017)
• Page Start: 1
• Page End: 13
• Publication Date: 2017-12
• Subjects: Biology -- Periodicals; Physical sciences -- Periodicals; 505
• DOI: 10.1038/s41467-017-02405-3
• Languages: English
• ISSNs: 2041-1723

Abstract

Abstract Dynamic assembly/disassembly of signaling complexes are crucial for cellular functions. Specialized latency and activation chaperones control the biogenesis of protein phosphatase 2A (PP2A) holoenzymes that contain a common scaffold and catalytic subunits and a variable regulatory subunit. Here we show that the butterfly-shaped TIPRL (TOR signaling pathway regulator) makes highly integrative multibranching contacts with the PP2A catalytic subunit, selective for the unmethylated tail and perturbing/inactivating the phosphatase active site. TIPRL also makes unusual wobble contacts with the scaffold subunit, allowing TIPRL, but not the overlapping regulatory subunits, to tolerate disease-associated PP2A mutations, resulting in reduced holoenzyme assembly and enhanced inactivation of mutant PP2A. Strikingly, TIPRL and the latency chaperone, α4, coordinate to disassemble active holoenzymes into latent PP2A, strictly controlled by methylation. Our study reveals a mechanism for methylation-responsive inactivation and holoenzyme disassembly, illustrating the complexity of regulation/signaling, dynamic complex disassembly, and disease mutations in cancer and intellectual disability. Protein phosphatase 2A (PP2A) forms different holoenzymes but little is known about the disassembly of these important signalling complexes. Here the authors present the crystal structure of PP2A bound to TOR signaling pathway regulator (TIPRL) and give insights into the methylation-dependent disassembly of PP2A holenzymes.