Recombinant Mouse Asporin (Aspn)

Function

Binds calcium and plays a role in osteoblast-driven collagen biomineralization activity (By similarity). Critical regulator of TGF-beta in articular cartilage and plays an essential role in cartilage homeostasis and osteoarthritis (OA) pathogenesis. Negatively regulates chondrogenesis in the articular cartilage by blocking the TGF-beta/receptor interaction on the cell surface and inhibiting the canonical TGF-beta/Smad signal. Negatively regulates periodontal ligament (PDL) differentiation and mineralization to ensure that the PDL is not ossified and to maintain homeostasis of the tooth-supporting system. Inhibits BMP2-induced cytodifferentiation of PDL cells by preventing its binding to BMPR1B/BMP type-1B receptor, resulting in inhibition of BMP-dependent activation of SMAD proteins. Inhibits the interaction between TGFB1 and TGF-beta receptor type II in the presence of heparin/heparan sulfate in vitro

Subcellular Location

Secreted, extracellular space, extracellular matrix

Tissue Specificity

Higher expression in heart, also detected in kidney, stomach, testes, and skin but only weakly in lung, skeletal muscle, small intestine, and thymus. Expressed specifically and predominantly in the periodontal ligament (PDL). During tooth development, strong expression is seen in the dental follicle, which is the progenitor tissue that forms cementum, alveolar bone, and the PDL. Expressed in the perichondria of the maxilla, mandible, vertebrae, and long bones. Predominantly expressed in the perichondrium/periosteum of long bones (at protein level)

Subunit

Interacts with type I collagen. DCN can inhibit collagen binding (By similarity). Interacts with TGFB1, TGFB2 and TGFB3. DCN, BGN, and FMOD inhibit binding to TGFB1. Interacts with BMP2. Interacts in vitro with type II collagen

• Lorenzo P. et al. Identification and characterization of asporin. A novel member of the leucine-rich repeat protein family closely related to decorin and biglycan. — J. Biol. Chem. (2001)
• Henry S.P. et al. Expression pattern and gene characterization of asporin. A newly discovered member of the leucine-rich repeat protein family. — J. Biol. Chem. (2001)
• Carninci P. et al. The transcriptional landscape of the mammalian genome. — Science (2005)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Yamada S. et al. PLAP-1/asporin, a novel negative regulator of periodontal ligament mineralization. — J. Biol. Chem. (2007)
• Nakajima M. et al. Mechanisms for asporin function and regulation in articular cartilage. — J. Biol. Chem. (2007)
• Kou I. et al. Expression and regulation of the osteoarthritis-associated protein asporin. — J. Biol. Chem. (2007)
• Tomoeda M. et al. PLAP-1/asporin inhibits activation of BMP receptor via its leucine-rich repeat motif. — Biochem. Biophys. Res. Commun. (2008)