Celio Cabral Oliveira, Eduardo Bassi Simoni, Mariana Abrahão Bueno Morais, Elizabeth Pacheco Batista Fontes, Pedro A Braga Dos Reis, Daisuke Urano, Alan M Jones
{"title":"A molecular dynamics study of membrane positioning for 7-transmembrane RGS proteins to modulate G-protein-mediated signaling in plants.","authors":"Celio Cabral Oliveira, Eduardo Bassi Simoni, Mariana Abrahão Bueno Morais, Elizabeth Pacheco Batista Fontes, Pedro A Braga Dos Reis, Daisuke Urano, Alan M Jones","doi":"10.1016/j.csbj.2025.04.013","DOIUrl":null,"url":null,"abstract":"<p><p>Protein phosphorylation regulates G protein signaling in plants. AtRGS1 primarily modulates AtGPA1, the canonical Gα subunit in the heterotrimeric G protein complex. AtRGS1 possesses both a seven-transmembrane (7TM) domain connected to a cytoplasmic Regulator of G Protein Signaling domain (RGS box domain) by a flexible linker region. This study presents the novel function of a highly conserved, known phosphorylation site, Ser278, within this linker region utilizing molecular dynamics (MD) simulations with <i>in vivo</i> experimental validation. We show that phosphorylation at Ser278 is crucial for establishing specific AtRGS1 interactions with AtGPA1, primarily by stabilizing the positioning and orientation of the RGS domain within the membrane. Phosphorylation at Ser278 enhances the formation of stable hydrogen bonds between phosphorylated Ser278 and conserved residues within the RGS box domain, influencing the flexibility of RGS domain mobility and thus modulating its interface to AtGPA1. Consistent with the MD simulations, <i>in vivo</i> assays demonstrated that this phosphorylation reduced the binding of AtRGS1 to AtGPA1 and conferred changes in physiology. Specifically, the non-phosphorylation mutation of Ser278 decreased both plant immune responses and AtRGS1 endocytosis evoked by the bacterial effector, flg22. MD simulations and sequence analysis of diverse plant 7TM-RGS proteins suggest conservation of this mechanism across land plants, emphasizing the critical role of this previously overlooked linker region.</p>","PeriodicalId":10715,"journal":{"name":"Computational and structural biotechnology journal","volume":"27 ","pages":"1529-1537"},"PeriodicalIF":4.4000,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12017998/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Computational and structural biotechnology journal","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1016/j.csbj.2025.04.013","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2025/1/1 0:00:00","PubModel":"eCollection","JCR":"Q2","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Protein phosphorylation regulates G protein signaling in plants. AtRGS1 primarily modulates AtGPA1, the canonical Gα subunit in the heterotrimeric G protein complex. AtRGS1 possesses both a seven-transmembrane (7TM) domain connected to a cytoplasmic Regulator of G Protein Signaling domain (RGS box domain) by a flexible linker region. This study presents the novel function of a highly conserved, known phosphorylation site, Ser278, within this linker region utilizing molecular dynamics (MD) simulations with in vivo experimental validation. We show that phosphorylation at Ser278 is crucial for establishing specific AtRGS1 interactions with AtGPA1, primarily by stabilizing the positioning and orientation of the RGS domain within the membrane. Phosphorylation at Ser278 enhances the formation of stable hydrogen bonds between phosphorylated Ser278 and conserved residues within the RGS box domain, influencing the flexibility of RGS domain mobility and thus modulating its interface to AtGPA1. Consistent with the MD simulations, in vivo assays demonstrated that this phosphorylation reduced the binding of AtRGS1 to AtGPA1 and conferred changes in physiology. Specifically, the non-phosphorylation mutation of Ser278 decreased both plant immune responses and AtRGS1 endocytosis evoked by the bacterial effector, flg22. MD simulations and sequence analysis of diverse plant 7TM-RGS proteins suggest conservation of this mechanism across land plants, emphasizing the critical role of this previously overlooked linker region.
期刊介绍:
Computational and Structural Biotechnology Journal (CSBJ) is an online gold open access journal publishing research articles and reviews after full peer review. All articles are published, without barriers to access, immediately upon acceptance. The journal places a strong emphasis on functional and mechanistic understanding of how molecular components in a biological process work together through the application of computational methods. Structural data may provide such insights, but they are not a pre-requisite for publication in the journal. Specific areas of interest include, but are not limited to:
Structure and function of proteins, nucleic acids and other macromolecules
Structure and function of multi-component complexes
Protein folding, processing and degradation
Enzymology
Computational and structural studies of plant systems
Microbial Informatics
Genomics
Proteomics
Metabolomics
Algorithms and Hypothesis in Bioinformatics
Mathematical and Theoretical Biology
Computational Chemistry and Drug Discovery
Microscopy and Molecular Imaging
Nanotechnology
Systems and Synthetic Biology