Department of Molecular Genetics, Utrecht University, Utrecht, The Netherlands ; Laboratorio Nacional de Genmica para la Biodiversidad, Cinvestav Sede Irapuato, Irapuato, Mexico.
PLoS Biol. 2013 Nov;11(11):e1001724. doi: 10.1371/journal.pbio.1001724. Epub 2013 Nov 26.
Quiescent long-term somatic stem cells reside in plant and animal stem cell niches. Within the Arabidopsis root stem cell population, the Quiescent Centre (QC), which contains slowly dividing cells, maintains surrounding short-term stem cells and may act as a long-term reservoir for stem cells. The RETINOBLASTOMA-RELATED (RBR) protein cell-autonomously reinforces mitotic quiescence in the QC. RBR interacts with the stem cell transcription factor SCARECROW (SCR) through an LxCxE motif. Disruption of this interaction by point mutation in SCR or RBR promotes asymmetric divisions in the QC that renew short-term stem cells. Analysis of the in vivo role of quiescence in the root stem cell niche reveals that slow cycling within the QC is not needed for structural integrity of the niche but allows the growing root to cope with DNA damage.
静止的长期体干细胞存在于植物和动物的干细胞龛中。在拟南芥根干细胞群体中，含有缓慢分裂细胞的静止中心（QC）维持周围的短期干细胞，并可能作为干细胞的长期储备库。REtinoblastoma-related（RBR）蛋白通过 LxCxE 基序自主增强 QC 中的有丝分裂静止。RBR 通过 LxCxE 基序与干细胞转录因子 SCARECROW（SCR）相互作用。通过 SCR 或 RBR 中的点突变破坏这种相互作用会促进 QC 中的不对称分裂，从而更新短期干细胞。对根干细胞龛中静止作用的体内作用的分析表明，QC 中的缓慢循环对于龛的结构完整性不是必需的，但允许生长的根应对 DNA 损伤。
