Reference - Detail
|Author||Shimono K, Fujishima K, Nomura T, Ohashi M, Usui T, Kengaku M, Toyoda A, Uemura T.|
|Title||An evolutionarily conserved protein CHORD regulates scaling of dendritic arbors with body size.|
Most organs scale proportionally with body size through regulation of individual cell size and/or cell number. Here we addressed how postmitotic and morphologically complex cells such as neurons scale with the body size by using the dendritic arbor of one Drosophila sensory neuron as an assay system. In small adults eclosed under a limited-nutrition condition, the wild-type neuron preserved the branching complexity of the arbor, but scaled down the entire arbor, making a "miniature". In contrast, mutant neurons for the Insulin/IGF signaling (IIS) or TORC1 pathway exhibited "undergrowth", which was characterized by decreases in both the branching complexity and the arbor size, despite a normal diet. These contrasting phenotypes hinted that a novel regulatory mechanism contributes to the dendritic scaling in wild-type neurons. Indeed, we isolated a mutation in the gene CHORD/morgana that uncoupled the neuron size and the body size: CHORD mutant neurons generated miniature dendritic arbors regardless of the body size. CHORD encodes an evolutionarily conserved co-chaperone of HSP90. Our results support the notion that dendritic growth and branching are controlled by partly separate mechanisms. The IIS/TORC1 pathways control both growth and branching to avert underdevelopment, whereas CHORD together with TORC2 realizes proportional scaling of the entire arbor.
|MeSH||Amino Acid Sequence Animals Body Size Carrier Proteins / genetics Carrier Proteins / metabolism* Cell Size Conserved Sequence* Dendrites / metabolism* Dendrites / ultrastructure Drosophila Proteins / genetics Drosophila Proteins / metabolism* Drosophila melanogaster / anatomy & histology Drosophila melanogaster / genetics* Drosophila melanogaster / growth & development Drosophila melanogaster / metabolism Evolution, Molecular Female Gene Expression Regulation, Developmental Insulin / genetics Insulin / metabolism Mechanistic Target of Rapamycin Complex 2 Molecular Chaperones / genetics Molecular Chaperones / metabolism* Molecular Sequence Data Multiprotein Complexes / genetics Multiprotein Complexes / metabolism Sensory Receptor Cells / metabolism* Sensory Receptor Cells / ultrastructure Signal Transduction TOR Serine-Threonine Kinases / genetics TOR Serine-Threonine Kinases / metabolism Transcription Factors / genetics Transcription Factors / metabolism|
|WOS Category||CELL BIOLOGY|