المؤلفون: Jiangqi Wen, Pengbo Liang, Jessica Folgmann, Thomas F. Stratil, Macarena Marín, Kirankumar S. Mysore, Claudia Popp, Thomas Ott

المصدر: Proceedings of the National Academy of Sciences. 115:5289-5294

مصطلحات موضوعية: 0106 biological sciences, 0301 basic medicine, Scaffold protein, Multidisciplinary, biology, Kinase, Chemistry, Mutant, fungi, Cell, Endocytosis, biology.organism_classification, 01 natural sciences, Medicago truncatula, Cell biology, 03 medical and health sciences, 030104 developmental biology, medicine.anatomical_structure, Membrane protein, medicine, Receptor, Actin, 010606 plant biology & botany

الوصف: Plant cell infection is tightly controlled by cell surface receptor-like kinases (RLKs) Alike other RLKs the Medicago truncatula entry receptor LYK3 laterally segregates into membrane nanodomains in a stimulus-dependent manner. Although nanodomain localization arises as a generic feature of plant membrane proteins, molecular mechanisms underlying such dynamic transitions and their functional relevance remained poorly understood. Here, we demonstrate that actin and the flotillin protein FLOT4 form the primary and indispensable core of a specific nanodomain. Infection-dependent induction of the remorin protein and secondary molecular scaffold SYMREM1 results in subsequent recruitment of ligand-activated LYK3 and its stabilization within these membrane subcompartments. Reciprocally, the majority of this LYK3 receptor pool is destabilized at the plasma membrane and undergoes rapid endocytosis in symrem1 mutants upon rhizobial inoculation resulting in premature abortion of host cell infections. These data reveal that receptor recruitment into nanodomains is indispensable for their function during host cell infection.SIGNIFICANCE STATEMENTPattern recognition receptors control the cellular entry of pathogenic as well as symbiotic microbes. While ligand-induced changes in receptor mobility at the plasma membrane and their localization in membrane nanodomains appears as a general feature, the molecular mechanism and the biological relevance of this phenomenon remained unknown. Here, we show that immobilization of the symbiotic cell entry receptor LYK3 in nanodomains requires the presence of actin and the two molecular scaffold proteins FLOT4 and SYMREM1. While FLOT4 forms the initial core structure, infection-induced expression and subsequent physical interaction of SYMREM1 with LYK3 stabilizes the activated receptors in membrane nanodomains. This recruitment prevents its stimulus-dependent endocytosis and ensures progression of the primary infection thread into root cortical cells.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::944b4860c571fbcbab8a174e4eb32afbTest
https://doi.org/10.1073/pnas.1721868115Test

المؤلفون: Sebastian S. A. Konrad, Thomas Ott, Jessica Folgmann, Veronika Thallmair, Iris K. Jarsch, Macarena Marín, Thomas F. Stratil, Claudia Popp

المصدر: New Phytologist. 203:758-769

مصطلحات موضوعية: Physiology, Acylation, Molecular Sequence Data, Plant Science, Biology, Structure-Activity Relationship, Membrane Microdomains, Amino Acid Sequence, Cysteine, Protein–lipid interaction, Integral membrane protein, Plant Proteins, Binding Sites, FERM domain, Peripheral membrane protein, S-acylation, Membrane transport, Phosphoproteins, Cell biology, Protein Transport, Sterols, Membrane protein, Mutation, Translocase of the inner membrane, lipids (amino acids, peptides, and proteins), Carrier Proteins, Peptides, Subcellular Fractions

الوصف: Remorins are well-established marker proteins for plasma membrane microdomains. They specifically localize to the inner membrane leaflet despite an overall hydrophilic amino acid composition. Here, we determined amino acids and post-translational lipidations that are required for membrane association of remorin proteins. We used a combination of cell biological and biochemical approaches to localize remorin proteins and truncated variants of those in living cells and determined S-acylation on defined residues in these proteins. S-acylation of cysteine residues in a C-terminal hydrophobic core contributes to membrane association of most remorin proteins. While S-acylation patterns differ between members of this multi-gene family, initial membrane association is mediated by protein-protein or protein-lipid interactions. However, S-acylation is not a key determinant for the localization of remorins in membrane microdomains. Although remorins bind via a conserved mechanism to the plasma membrane, other membrane-resident proteins may be involved in the recruitment of remorins into membrane domains. S-acylation probably occurs after an initial targeting of the proteins to the plasma membrane and locks remorins in this compartment. As S-acylation is a reversible post-translational modification, stimulus-dependent intracellular trafficking of these proteins can be envisioned.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::d198bddfcdf7b013093a9fb34af65027Test
https://doi.org/10.1111/nph.12867Test

المؤلفون: Thomas Ott, Veronika Thallmair, Macarena Marín

المصدر: Journal of Biological Chemistry. 287:39982-39991

مصطلحات موضوعية: Protein family, Arabidopsis, Plant Biology, chemical and pharmacologic phenomena, Importin, Karyopherins, Biology, Intrinsically disordered proteins, Biochemistry, Protein–protein interaction, Protein structure, Protein-fragment complementation assay, Protein Isoforms, Protein phosphorylation, Molecular Biology, Plant Proteins, Arabidopsis Proteins, fungi, food and beverages, Cell Biology, biochemical phenomena, metabolism, and nutrition, Phosphoproteins, Protein Structure, Tertiary, Membrane protein, Biophysics, bacteria, Protein Multimerization, Carrier Proteins

الوصف: The longstanding structure-function paradigm, which states that a protein only serves a biological function in a structured state, had to be substantially revised with the description of intrinsic disorder in proteins. Intrinsically disordered regions that undergo a stimulus-dependent disorder-to-order transition are common to a large number of signaling proteins. However, little is known about the functionality of intrinsically disordered regions in plant proteins. Here we investigated intrinsic disorder in a plant-specific remorin protein that has been described as a signaling component in plant-microbe interactions. Using bioinformatic, biochemical, and biophysical approaches, we characterized the highly abundant remorin AtREM1.3, showing that its N-terminal region is intrinsically disordered. Although only the AtREM1.3 C-terminal domain is essential for stable homo-oligomerization, the N-terminal region facilitates this interaction. Furthermore, we confirmed the stable interaction between AtREM1.3 and four isoforms of the importin α protein family in a yeast two-hybrid system and by an in planta bimolecular fluorescent complementation assay. Phosphorylation of Ser-66 in the intrinsically disordered N-terminal region decreases the interaction strength with the importin α proteins. Hence, the N-terminal region may constitute a regulatory domain, stabilizing these interactions.

الوصول الحر: https://explore.openaire.eu/search/publication?articleId=doi_dedup___::80af7da0404952f43589855eef9a291cTest
https://doi.org/10.1074/jbc.m112.414292Test