Knight M Noelle, Hankenson Kurt D
Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, United States; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, United States.
Department of Clinical Studies-New Bolton Center, School of Veterinary Medicine, University of Pennsylvania, United States; Department of Orthopaedic Surgery, Perelman School of Medicine, University of Pennsylvania, United States.
Matrix Biol. 2014 Jul;37:157-61. doi: 10.1016/j.matbio.2014.06.003. Epub 2014 Jun 27.
R-spondins are a family of four matricellular proteins produced by a variety of cell-types. Structurally, R-spondins contain a TSR1 domain that retains the tryptophan structure and a modified cysteine-rich CSVCTG region. In addition, the R-spondins contain two furin repeats implicated in canonical Wnt signaling. R-spondins positively regulate canonical Wnt signaling by reducing Wnt receptor turnover and thereby increasing beta-catenin stabilization. R-spondins are prominently expressed in the developing skeleton and contribute to limb formation, particularly of the distal digit. Additionally, results suggest that R-spondins may contribute to the maintenance of adult bone mass by regulating osteoblastogenesis and bone formation.
R-spondin蛋白是由多种细胞类型产生的四种基质细胞蛋白家族。在结构上，R-spondin蛋白包含一个保留色氨酸结构的TSR1结构域和一个修饰的富含半胱氨酸的CSVCTG区域。此外，R-spondin蛋白包含两个与经典Wnt信号传导相关的弗林蛋白酶重复序列。R-spondin蛋白通过减少Wnt受体更新从而增加β-连环蛋白稳定性来正向调节经典Wnt信号传导。R-spondin蛋白在发育中的骨骼中显著表达，并有助于肢体形成，特别是远端指骨。此外，结果表明R-spondin蛋白可能通过调节成骨细胞生成和骨形成来维持成人骨量。
