Glycine rich segments adopt polyproline II helices: Implications for biomolecular condensate formation
| Autor: | Miguel Mompeán, Eurico J. Cabrita, S.S. Félix, Andrew J. Doig, Miguel A. Treviño, R. López-Sánchez, David Pantoja-Uceda, Javier Oroz, Bethan S. McAvan, Douglas V. Laurents |
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| Přispěvatelé: | La Caixa, Ministerio de Economía y Competitividad (España), Agencia Estatal de Investigación (España), Ministerio de Ciencia e Innovación (España), UCB Pharma |
| Rok vydání: | 2021 |
| Předmět: |
Models
Molecular 0301 basic medicine Circular dichroism Magnetic Resonance Spectroscopy Stereochemistry Population Glycine Biophysics Molecular dynamics Intrinsically disordered proteins Biochemistry Protein Structure Secondary 03 medical and health sciences CD Spectroscopy NMR spectroscopy Antifreeze protein Side chain education Molecular Biology Polyproline helix education.field_of_study 030102 biochemistry & molecular biology Chemistry Circular Dichroism Nuclear magnetic resonance spectroscopy FTIR spectroscopy 030104 developmental biology Polyproline II helices Bimolecular condensates Peptides |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname |
| Popis: | Supplementary data related to this article can be found at https://doi.org/10.1016/j.abb.2021.108867. Many intrinsically disordered proteins contain Gly-rich regions which are generally assumed to be disordered. Such regions often form biomolecular condensates which play essential roles in organizing cellular processes. However, the bases of their formation and stability are still not completely understood. Based on NMR studies of the Gly-rich H. harveyi "snow flea" antifreeze protein, we recently proposed that Gly-rich sequences, such as the third "RGG" region of Fused in Sarcoma (FUS) protein, may adopt polyproline II helices whose association might stabilize condensates. Here, this hypothesis is tested with a polypeptide corresponding to the third RGG region of FUS. NMR spectroscopy and molecular dynamics simulations suggest that significant populations of polyproline II helix are present. These findings are corroborated in a model peptide Ac-RGGYGGRGGWGGRGGY-NH2, where a peak characteristic of polyproline II helix is observed using CD spectroscopy. Its intensity suggests a polyproline II population of 40%. This result is supported by data from FTIR and NMR spectroscopies. In the latter, NOE correlations are observed between the Tyr and Arg, and Arg and Trp side chain hydrogens, confirming that side chains spaced three residues apart are close in space. Taken together, the data are consistent with a polyproline II helix, which is bent to optimize interactions between guanidinium and aromatic moieties, in equilibrium with a statistical coil ensemble. These results lend credence to the hypothesis that Gly-rich segments of disordered proteins may form polyproline II helices which help stabilize biomolecular condensates. This study was supported by projects: LCF/BQ/PR19/11700003 from “La Caixa Foundation” (ID 100010434) to M.M., BBSRC CASE award with UCB Pharma BB/L014734/1 to AJD, and SAF2016-76678-C2-2-R, 2019AEP121 and BTC-PID2019-109306RB-I00 to DVL from the Spanish Ministry of Economy and Competitivity, the Spanish National Research Council and the Spanish Ministry of Science and Innovation, respectively. The authors acknowledge FCT-Portugal for the PhD studentship attributed to Sara S. Félix (PD/BD/148028/2019). J.O. is a Ramón y Cajal Fellow of the Spanish AEI Ministry of Science and Innovation, and a Leondardo Fellow from the BBVA Foundation (grant number BBM-TRA-0203). NMR experiments were performed in the “Manuel Rico” NMR Laboratory (LMR) of the Spanish National Research Council (CSIC), a node of the Spanish Large-Scale National Facility (ICTS R-LRB). We are grateful to Dr. José Varela Espinosa, Emilia Aporta Sosa and Cristina Quevedo Sierra (MS-CIB/CSIC) for expert technical work with peptide synthesis. |
| Databáze: | OpenAIRE |
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