TY - JOUR
T1 - Hmgb1 can facilitate activation of the matrilin-1 gene promoter by Sox9 and L-Sox5/Sox6 in early steps of chondrogenesis
AU - Szénási, Tibor
AU - Kénesi, Erzsébet
AU - Nagy, Andrea
AU - Molnár, Annamária
AU - Bálint, Bálint László
AU - Zvara, gnes
AU - Csabai, Zsolt
AU - Deák, Ferenc
AU - Boros Oláh, Beáta
AU - Mátés, Lajos
AU - Nagy, László
AU - Puskás, László G.
AU - Kiss, Ibolya
N1 - Funding Information:
This work was supported by grants OTKA T049608 (to I.K.), PD50006 (to E.K.) and PD101421 (to L.M.) from the Hungarian National Scientific Research Foundation and by grants GVOP-3.1.1.-2004-05-0290/3.0 (to I.K.) and GOP-1.1.1-11-2011-0003 (to Avidin Ltd) from the Economic Competitiveness Operative Programme of the National Development Plan . Á.Z. and B.L.B. were supported by János Bolyai fellowship of Hungarian Academy of Sciences ( BO/00781/11 and BO/795/08 ). B.L.B. was also supported by Szodoray Fellowship of the University of Debrecen . ChIP experiments were performed at the Center for Clinical Genomics and Personalized Medicine of the University of Debrecen.
PY - 2013/10
Y1 - 2013/10
N2 - The architectural high mobility group box 1 (Hmgb1) protein acts as both a nuclear and an extracellular regulator of various biological processes, including skeletogenesis. Here we report its contribution to the evolutionarily conserved, distinctive regulation of the matrilin-1 gene (Matn1) expression in amniotes. We previously demonstrated that uniquely assembled proximal promoter elements restrict Matn1 expression to specific growth plate cartilage zones by allowing varying doses of L-Sox5/Sox6 and Nfi proteins to fine-tune their Sox9-mediated transactivation. Here, we dissected the regulatory mechanisms underlying the activity of a conserved distal promoter element 1. We show that this element carries three Sox-binding sites, works as an enhancer in vivo, and allows promoter activation by the Sox5/6/9 chondrogenic trio. In early steps of chondrogenesis, declining Hmgb1 expression overlaps with the onset of Sox9 expression. Unlike repression in late steps, Hmgb1 overexpression in early chondrogenesis increases Matn1 promoter activation by the Sox trio, and forced Hmgb1 expression in COS-7 cells facilitates induction of Matn1 expression by the Sox trio. The conserved Matn1 control elements bind Hmgb1 and SOX9 with opposite efficiency in vitro. They show higher HMGB1 than SOX trio occupancy in established chondrogenic cell lines, and HMGB1 silencing greatly increases MATN1 and COL2A1 expression. Together, these data thus suggest a model whereby Hmgb1 helps recruit the Sox trio to the Matn1 promoter and thereby facilitates activation of the gene in early chondrogenesis. We anticipate that Hmgb1 may similarly affect transcription of other cartilage-specific genes.
AB - The architectural high mobility group box 1 (Hmgb1) protein acts as both a nuclear and an extracellular regulator of various biological processes, including skeletogenesis. Here we report its contribution to the evolutionarily conserved, distinctive regulation of the matrilin-1 gene (Matn1) expression in amniotes. We previously demonstrated that uniquely assembled proximal promoter elements restrict Matn1 expression to specific growth plate cartilage zones by allowing varying doses of L-Sox5/Sox6 and Nfi proteins to fine-tune their Sox9-mediated transactivation. Here, we dissected the regulatory mechanisms underlying the activity of a conserved distal promoter element 1. We show that this element carries three Sox-binding sites, works as an enhancer in vivo, and allows promoter activation by the Sox5/6/9 chondrogenic trio. In early steps of chondrogenesis, declining Hmgb1 expression overlaps with the onset of Sox9 expression. Unlike repression in late steps, Hmgb1 overexpression in early chondrogenesis increases Matn1 promoter activation by the Sox trio, and forced Hmgb1 expression in COS-7 cells facilitates induction of Matn1 expression by the Sox trio. The conserved Matn1 control elements bind Hmgb1 and SOX9 with opposite efficiency in vitro. They show higher HMGB1 than SOX trio occupancy in established chondrogenic cell lines, and HMGB1 silencing greatly increases MATN1 and COL2A1 expression. Together, these data thus suggest a model whereby Hmgb1 helps recruit the Sox trio to the Matn1 promoter and thereby facilitates activation of the gene in early chondrogenesis. We anticipate that Hmgb1 may similarly affect transcription of other cartilage-specific genes.
KW - Cartilage-specific regulation
KW - Chromatin immunoprecipitation
KW - Growth plate
KW - Matrilin
KW - Silencing
KW - Transgenic mice
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U2 - 10.1016/j.bbagrm.2013.07.004
DO - 10.1016/j.bbagrm.2013.07.004
M3 - Article
C2 - 23860260
AN - SCOPUS:84881242676
SN - 1874-9399
VL - 1829
SP - 1075
EP - 1091
JO - Biochimica et Biophysica Acta - Gene Regulatory Mechanisms
JF - Biochimica et Biophysica Acta - Gene Regulatory Mechanisms
IS - 10
ER -