Identification and characterization of Runx2 phosphorylation sites involved in matrix metalloproteinase-13 promoter activation.
Matrix metalloproteinase-13 (MMP-13) plays a critical role in parathyroid hormone (PTH)-induced bone resorption. PTH acts via protein kinase A (PKA) to phosphorylate and stimulate the transactivation of Runx2 for MMP-13 promoter activation. We show here that PTH stimulated Runx2 phosphorylation in rat osteoblastic cells. Runx2 was phosphorylated on serine 28 and threonine 340 after 8-bromo cyclic adenosine mono phosphate (8-Br-cAMP) treatment. We further demonstrate that in the presence of 8-Br-cAMP, the wild-type Runx2 construct stimulated MMP-13 promoter activity, while the Runx2 construct having mutations at three phosphorylation sites (S28, S347 and T340) was unable to stimulate MMP-13 promoter activity. Thus, we have identified the Runx2 phosphorylation sites necessary for PKA stimulated MMP-13 promoter activation and this event may be critical for bone remodeling.
Selvamurugan
Nagarajan
N
Department of Endocrinology, Dr. ALM Post Graduate Institute of Basic Medical Sciences, University of Madras, Taramani, Chennai, India.
Shimizu
Emi
E
Lee
Minnkyong
M
Liu
Tong
T
Li
Hong
H
Partridge
Nicola C
NC
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000494:pharmacology; D000818:Animals; D016723:Bone Remodeling / Q000187:drug effects / Q000502:physiology; D019556:COS Cells; D002522:Chlorocebus aethiops; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism; D004790:Enzyme Induction / Q000187:drug effects / Q000502:physiology; D053509:Matrix Metalloproteinase 13 / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D009154:Mutation; D010281:Parathyroid Hormone / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000502:physiology*; D015533:Transcriptional Activation / Q000187:drug effects / Q000502:physiology*
D050659:Core Binding Factor Alpha 1 Subunit; D010281:Parathyroid Hormone; C493716:Runx2 protein, mouse; D015124:8-Bromo Cyclic Adenosine Monophosphate; D017868:Cyclic AMP-Dependent Protein Kinases; D053509:Matrix Metalloproteinase 13