title: Balanced nucleocytosolic partitioning defines a spatial network to coordinate circadian physiology in plants.
abstract: Biological networks consist of a defined set of regulatory motifs. Subcellular compartmentalization of regulatory molecules can provide a further dimension in implementing regulatory motifs. However, spatial regulatory motifs and their roles in biological networks have rarely been explored. Here we show, using experimentation and mathematical modeling, that spatial segregation of GIGANTEA (GI), a critical component of plant circadian systems, into nuclear and cytosolic compartments leads to differential functions as positive and negative regulators of the circadian core gene, LHY, forming an incoherent feedforward loop to regulate LHY. This regulatory motif formed by nucleocytoplasmic partitioning of GI confers, through the balanced operation of the nuclear and cytosolic GI, strong rhythmicity and robustness to external and internal noises to the circadian system. Our results show that spatial and functional segregation of a single molecule species into different cellular compartments provides a means for extending the regulatory capabilities of biological networks.
authors.affiliation: Department of New Biology, DGIST, Daegu 711-873, Republic of Korea.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Kim
authors.forename: Seungmin
authors.initials: S
authors.lastname: Han
authors.forename: Miji
authors.initials: M
authors.lastname: Yeom
authors.forename: Hyunmin
authors.initials: H
authors.lastname: Kim
authors.forename: Junhyun
authors.initials: J
authors.lastname: Lim
authors.forename: Joon-Yung
authors.initials: JY
authors.lastname: Cha
authors.forename: Woe-Yeon
authors.initials: WY
authors.lastname: Kim
authors.forename: David E
authors.initials: DE
authors.lastname: Somers
authors.forename: Joanna
authors.initials: J
authors.lastname: Putterill
authors.forename: Hong Gil
authors.initials: HG
authors.lastname: Nam
authors.forename: Daehee
authors.initials: D
authors.lastname: Hwang
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology*; D003198:Computer Simulation; D003600:Cytosol / Q000378:metabolism*; D018744:DNA, Plant / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D035264:Flowers / Q000235:genetics / Q000502:physiology; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D008954:Models, Biological; D010788:Photosynthesis; D018515:Plant Leaves / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D054730:Protein Interaction Domains and Motifs; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant; D004268:DNA-Binding Proteins; C121183:GI protein, Arabidopsis; C113192:LHY protein, Arabidopsis; D014157:Transcription Factors