title: A functionally required unfoldome from the plant kingdom: intrinsically disordered N-terminal domains of GRAS proteins are involved in molecular recognition during plant development.
abstract: The intrinsic disorder is highly abundant in eukaryotic genomes. In the animal kingdom, numerous intrinsically disordered proteins (IDPs) have been characterized, especially in cell signalling and transcription regulation. An intrinsically disordered region often folds in different structures allowing an IDP to recognize and bind different partners at various binding interfaces. In contrast, there have only been a few reports of IDPs from the plant kingdom. Plant-specific GRAS proteins play critical and diverse roles in plant development and signalling and often act as integrators of signals from multiple plant growth regulatory inputs. Using computational and bioinformatics tools, we demonstrate here that the GRAS proteins are intrinsically disordered, thus forming the first functionally required unfoldome in the plant kingdom. Furthermore, the N-terminal domains of GRAS proteins are predicted to contain numerous Molecular Recognition Features (MoRFs), short interaction-prone segments that are located within extended disorder regions and are able to recognize their interacting partners and to undergo disorder-to-order transitions upon binding to these specific partners. Overlapping with the relatively conserved motifs in the N-terminal domains of GRAS proteins, these predicted MoRFs represent the potential protein-protein binding sites and may be involved in molecular recognition during plant development. This study enables us to propose a conceptual framework that guides future experimental approaches to understand structure-function relationships of the entire GRAS family.
authors: The New Zealand Institute for Plant and Food Research, Private Bag 11030, Palmerston North, New Zealand. Xiaolin.Sun@plantandfood.co.nz
authors: Xiaolin
authors: X
authors: Sun
authors: Bin
authors: B
authors: Xue
authors: William T
authors: WT
authors: Jones
authors: Erik
authors: E
authors: Rikkerink
authors: A Keith
authors: AK
authors: Dunker
authors: Vladimir N
authors: VN
authors: Uversky
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D001665:Binding Sites / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D018506:Gene Expression Regulation, Plant; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010766:Phosphorylation; D010802:Phylogeny; D063245:Plant Development; D010944:Plants / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000235:genetics
chemical_list: D029681:Arabidopsis Proteins; C109555:GAI protein, Arabidopsis; C508468:RGA protein, Arabidopsis; D012097:Repressor Proteins; C100978:SCR protein, Arabidopsis