title: R-spondins: novel matricellular regulators of the skeleton.
abstract: 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.
authors: 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.
authors: M Noelle
authors: MN
authors: Knight
authors: 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. Electronic address: kdhank@vet.upenn.edu.
authors: Kurt D
authors: KD
authors: Hankenson
mesh_terms: D020816:Amino Acid Motifs / Q000235:genetics; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008954:Models, Biological; D008969:Molecular Sequence Data; D010012:Osteogenesis / Q000502:physiology*; D017434:Protein Structure, Tertiary; D019699:Thrombospondins / Q000378:metabolism*; D060449:Wnt Signaling Pathway / Q000502:physiology*; D051176:beta Catenin / Q000378:metabolism; D000098907:R-Spondins
chemical_list: D016326:Extracellular Matrix Proteins; D036341:Intercellular Signaling Peptides and Proteins; D019699:Thrombospondins; D051176:beta Catenin; C503243:RSPO1 protein, human; D000098907:R-Spondins; C475438:RSPO3 protein, human; C516169:RSPO4 protein, human; C557408:Rspo2 protein, human
keywords: Beta-catenin; Bone; Matricellular; Osteoblast; R-spondin; Thrombospondin