title: The intrinsically disordered N-terminal region of AtREM1.3 remorin protein mediates protein-protein interactions.
abstract: 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.
authors.affiliation: Institute of Genetics, Ludwig-Maximilians University of Munich, Grosshaderner Strasse 2-4, Martinsried 82152, Germany. macarena.marin@bio.lmu.de
authors.forename: Macarena
authors.initials: M
authors.lastname: Marín
authors.forename: Veronika
authors.initials: V
authors.lastname: Thallmair
authors.forename: Thomas
authors.initials: T
authors.lastname: Ott
mesh_terms: D017360:Arabidopsis / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D028884:Karyopherins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D020033:Protein Isoforms / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055503:Protein Multimerization / Q000502:physiology*; D017434:Protein Structure, Tertiary
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D028884:Karyopherins; D010750:Phosphoproteins; D010940:Plant Proteins; D020033:Protein Isoforms; C535122:importin alpha, Arabidopsis; C103794:remorin