RNA-binding protein SAMD4 regulates skeleton development through translational inhibition of Mig6 expression.
Protein translation regulation has essential roles in inflammatory responses, cancer initiation and the pathogenesis of several neurodegenerative disorders. However, the role of the regulation of protein translation in mammalian skeleton development has been rarely elaborated. Here we report that the lack of the RNA-binding protein sterile alpha motif domain containing protein 4 (SAMD4) resulted in multiple developmental defects in mice, including delayed bone development and decreased osteogenesis. Samd4-deficient mesenchymal progenitors exhibit impaired osteoblast differentiation and function. Mechanism study demonstrates that SAMD4 binds the Mig6 mRNA and inhibits MIG6 protein synthesis. Consistent with this, Samd4-deficient cells have increased MIG6 protein level and knockdown of Mig6 rescues the impaired osteogenesis in Samd4-deficient cells. Furthermore, Samd4-deficient mice also display chondrocyte defects, which is consistent with the regulation of MIG6 protein level by SAMD4. These findings define SAMD4 as a previously unreported key regulator of osteoblastogenesis and bone development, implying that regulation of protein translation is an important mechanism governing skeletogenesis and that control of protein translation could have therapeutic potential in metabolic bone diseases, such as osteoporosis.
State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Sciences, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences , Shanghai, China.
Ningning
N
Niu
State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Sciences, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences , Shanghai, China.
Jian-Feng
JF
Xiang
Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai, China.
Qin
Q
Yang
State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Sciences, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences , Shanghai, China.
Lijun
L
Wang
Metabolic Bone Disease and Genetic Research Unit, Division of Osteoporosis and Bone Disease, Department of Endocrinology and Metabolism, Shanghai Jiao Tong University Affiliated Six People's Hospital , Shanghai, China.
Zhanying
Z
Wei
State Key Laboratory of Molecular Biology, CAS Center for Excellence in Molecular Cell Sciences, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences , Shanghai, China.
Ling-Ling
0000-0001-9501-0305
LL
Chen
Key Laboratory of Computational Biology, CAS-MPG Partner Institute for Computational Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences , Shanghai, China.
Li
L
Yang
State Key Laboratory of Cell Biology, CAS Center for Excellence in Molecular Cell Sciences, Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences , Shanghai, China.
Weiguo
W
Zou
Mig6; SAMD4; bone development; chondrocyte; osteoblast; translational repression