FAD104, a regulatory factor of adipogenesis, acts as a novel regulator of calvarial bone formation.
Osteogenesis is a complex process that is orchestrated by several growth factors, extracellular cues, signaling molecules, and transcriptional factors. Understanding the mechanisms of bone formation is pivotal for clarifying the pathogenesis of bone diseases. Previously, we reported that fad104 (factor for adipocyte differentiation 104), a novel positive regulator of adipocyte differentiation, negatively regulated the differentiation of mouse embryonic fibroblasts into osteocytes. However, the physiological role of fad104 in bone formation has not been elucidated. Here, we clarified the role of fad104 in bone formation in vivo and in vitro. fad104 disruption caused craniosynostosis-like premature ossification of the calvarial bone. Furthermore, analyses using primary calvarial cells revealed that fad104 negatively regulated differentiation and BMP/Smad signaling pathway. FAD104 interacted with Smad1/5/8. The N-terminal region of FAD104, which contains a proline-rich motif, was capable of binding to Smad1/5/8. We demonstrated that down-regulation of Smad1/5/8 phosphorylation by FAD104 is dependent on the N-terminal region of FAD104 and that fad104 functions as a novel negative regulator of BMP/Smad signaling and is required for proper development for calvarial bone. These findings will aid a comprehensive description of the mechanism that controls normal and premature calvarial ossification.
From the Department of Molecular Biology, Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori, Mizuho-ku, Nagoya, Aichi 467-8603, Japan.
Keishi
K
Kishimoto
Makoto
M
Nishizuka
Daiki
D
Katoh
Ayumi
A
Kato
Shigehiro
S
Osada
Masayoshi
M
Imagawa
D050156:Adipogenesis / Q000502:physiology; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D003398:Craniosynostoses / Q000196:embryology / Q000235:genetics / Q000473:pathology; D015536:Down-Regulation / Q000502:physiology; D005353:Fibronectins / Q000096:biosynthesis* / Q000235:genetics; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D053505:Matrix Metalloproteinases, Secreted / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D010012:Osteogenesis / Q000502:physiology*; D010766:Phosphorylation / Q000502:physiology; D017434:Protein Structure, Tertiary; D015398:Signal Transduction / Q000502:physiology*; D012886:Skull / Q000196:embryology*; D051785:Smad Proteins / Q000235:genetics / Q000378:metabolism
C538837:Fndc3b protein, mouse; D005353:Fibronectins; D051785:Smad Proteins; D053505:Matrix Metalloproteinases, Secreted
Adipogenesis; Bone; Bone Morphogenetic Protein (BMP); Calvarial Bone Formation; Osteoblasts; SMAD Transcription Factor