SATB2 is a multifunctional determinant of craniofacial patterning and osteoblast differentiation.
Vertebrate skeletogenesis involves two processes, skeletal patterning and osteoblast differentiation. Here, we show that Satb2, encoding a nuclear matrix protein, is expressed in branchial arches and in cells of the osteoblast lineage. Satb2-/- mice exhibit both craniofacial abnormalities that resemble those observed in humans carrying a translocation in SATB2 and defects in osteoblast differentiation and function. Multiple osteoblast-specific genes were identified as targets positively regulated by SATB2. In addition, SATB2 was found to repress the expression of several Hox genes including Hoxa2, an inhibitor of bone formation and regulator of branchial arch patterning. Molecular analysis revealed that SATB2 directly interacts with and enhances the activity of both Runx2 and ATF4, transcription factors that regulate osteoblast differentiation. This synergy was genetically confirmed by bone formation defects in Satb2/Runx2 and Satb2/Atf4 double heterozygous mice. Thus, SATB2 acts as a molecular node in a transcriptional network regulating skeletal development and osteoblast differentiation.
Dobreva
Gergana
G
Max-Planck Institute of Immunobiology, Department of Cellular and Molecular Immunology, 79108 Freiburg, Germany.
Chahrour
Maria
M
Dautzenberg
Marcel
M
Chirivella
Laura
L
Kanzler
Benoit
B
Fariñas
Isabel
I
Karsenty
Gerard
G
Grosschedl
Rudolf
R
D051701:Activating Transcription Factor 4 / Q000235:genetics; D000818:Animals; D019521:Body Patterning / Q000235:genetics; D001934:Branchial Region / Q000002:abnormalities / Q000166:cytology / Q000378:metabolism; D002454:Cell Differentiation / Q000235:genetics; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics; D019465:Craniofacial Abnormalities / Q000235:genetics* / Q000378:metabolism / Q000503:physiopathology; D005147:Facial Bones / Q000002:abnormalities* / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental / Q000235:genetics; D005801:Genes, Homeobox / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics; D036961:Matrix Attachment Region Binding Proteins / Q000235:genetics*; D051379:Mice; D018345:Mice, Knockout; D009154:Mutation / Q000235:genetics; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics; D012886:Skull / Q000002:abnormalities*; D014157:Transcription Factors / Q000235:genetics*
C081452:Atf4 protein, mouse; D050659:Core Binding Factor Alpha 1 Subunit; D018398:Homeodomain Proteins; C489833:Hoxa2 protein, mouse; D036961:Matrix Attachment Region Binding Proteins; D012097:Repressor Proteins; C493716:Runx2 protein, mouse; C501473:SATB2 protein, mouse; D014157:Transcription Factors; D051701:Activating Transcription Factor 4