B56δ long- disordered arms form a dynamic PP2A regulation interface coupled with global allostery and Jordan's syndrome mutations

• 成果类型: Article
• 署名作者: Wu, Cheng- Guo; Balakrishnan, Vijaya K.; Merrill, Ronald A.; Parihar, Pankaj S.; Konovolov, Kirill; Chen, Yu- Chia; Xu, Zhen; Wei, Hui; Sundaresan, Ramya; Cui, Qiang; Wadzinski, Brian E.; Swingle, Mark R.; Musiyenko, Alla; Chung, Wendy K.; Honkanen, Richard E.; Suzuki, Aussie; Huang, Xuhui; Strack, Stefan; Xing, Yongna
• 署名单位: University of Wisconsin System; University of Wisconsin Madison; University of Wisconsin System; University of Wisconsin Madison; University of Iowa; University of Wisconsin System; University of Wisconsin Madison; University of Wisconsin System; University of Wisconsin Madison; University of Iowa; Boston University; Vanderbilt University; University of South Alabama; Harvard University; Harvard Medical School; Harvard University Medical Affiliates; Boston Children's Hospital
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-14478
• DOI: 10.1073/pnas.2310727120
• 发表日期: 2024-01-02
• 关键词: protein phosphatase 2a; crystal-structure; c-myc; dephosphorylation; phosphorylation; binding; motifs; specificity; algorithms; efficient

摘要

Intrinsically disordered regions (IDR) and short linear motifs (SLiMs) play pivotal roles in the intricate signaling networks governed by phosphatases and kinases. B568 (encoded by PPP2R5D) is a regulatory subunit of protein phosphatase 2A (PP2A) with long IDRs that harbor a substrate- mimicking SLiM and multiple phosphorylation sites. De novo missense mutations in PPP2R5D cause intellectual disabilities (ID), macrocephaly, Parkinsonism, and a broad range of neurological symptoms. Our single- particle cryo-EM structures of the PP2A-B568 holoenzyme reveal that the long, disordered arms at the B568 termini fold against each other and the holoenzyme core. This architecture suppresses both the phosphatase active site and the substrate- binding protein groove, thereby stabilizing the enzyme in a closed latent form with dual autoinhibition. The resulting interface spans over 190 angstrom and harbors unfavorable contacts, activation phosphorylation sites, and nearly all residues with ID- associated mutations. Our studies suggest that this dynamic interface is coupled to an allosteric network responsive to phosphorylation and altered globally by mutations. Furthermore, we found that ID mutations increase the holoenzyme activity and perturb the phosphorylation rates, and the severe variants significantly increase the mitotic duration and error rates compared to the normal variant.