A tethering mechanism underlies Pin1-catalyzed proline cis-trans isomerization at a noncanonical site

• 成果类型: Article
• 署名作者: Williams, Christopher C.; Chuck, Jonathan; Munoz-Tello, Paola; Kojetin, Douglas J.
• 署名单位: State University System of Florida; University of Florida; Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology; State University System of Florida; University of Florida; Herbert Wertheim UF Scripps Institute for Biomedical Innovation & Technology; State University System of Florida; University of Florida; Vanderbilt University; Vanderbilt University; Vanderbilt University; Vanderbilt University
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10561
• DOI: 10.1073/pnas.2414606122
• 发表日期: 2025-05-27
• 关键词: prolyl-isomerase pin1; activated receptor-gamma; substrate recognition; nuclear receptors; ppar-gamma; phosphorylation; domain; transactivation; DYNAMICS; binding

摘要

The prolyl isomerase Pin1 catalyzes the cis-trans isomerization of proline peptide bonds, a noncovalent posttranslational modification that influences cellular and molecular processes, including protein-protein interactions. Pin1 is a two-domain enzyme containing a WW domain that recognizes phosphorylated serine/threonine-proline (pS/pT-P) canonical motifs and an enzymatic PPIase domain that catalyzes proline cis-trans isomerization of pS/pT-P motifs. Here, we show that Pin1 uses a tethering mechanism to bind and catalyze proline cis-trans isomerization of a noncanonical motif in the disordered N-terminal activation function-1 (AF-1) domain of the human nuclear receptor PPAR gamma. NMR reveals multiple Pin1 binding regions within the PPAR gamma AF-1, including a canonical motif (pS112-P113) that when phosphorylated by the kinase ERK2 binds the Pin1 WW domain with high affinity. NMR methods reveal that Pin1 also binds and accelerates cis-trans isomerization of a noncanonical motif containing a tryptophan-proline motif (W39-P40) previously shown to be involved in an interdomain interaction with the C-terminal ligand-binding domain (LBD) of PPAR gamma. Cellular transcription studies combined with mutagenesis and Pin1 inhibitor treatment reveal a functional role for Pin1-mediated acceleration of cis-trans isomerization of the PPAR gamma W39-P40 motif. Our data inform a refined model of the Pin1 catalytic mechanism where the WW domain can bind a canonical pS/T-P motif and tether Pin1 to a target, which enables the PPIase domain to exert catalytic cis-trans isomerization at a distal noncanonical site.