TY - JOUR
T1 - Fibroblast growth factor receptor 3 gene transcription is suppressed by cyclic adenosine 3',5'-monophosphate. Identification of a chondrocytic regulatory element
AU - McEwen, Donald G.
AU - Green, Rebecca P.
AU - Naski, Michael C.
AU - Towler, Dwight A.
AU - Ornitz, David M.
PY - 1999/10/22
Y1 - 1999/10/22
N2 - Signaling through fibroblast growth factor receptors (FGFRs) is critical for the development and patterning of the vertebrate skeleton. Gain-of- function alleles of fgfr2 and fgfr3 have been linked to several dominant skeletal disorders in humans, while null mutations in fgfr3 result in the overgrowth of long bones in a mouse model system. Interestingly, the expression pattern of fgfr3 in growth plate chondrocytes overlaps that of the parathyroid hormone (PTH)-related peptide (PTHrP) receptor, a signaling molecule that also regulates endochondral ossification. The coincident expression of these two receptors suggests that their signaling pathways may also interact. To gain insight into the regulatory mechanism(s) that govern the expression of the fgfr3 gene in chondrocytes, we have identified a cell- specific transcriptional regulatory element (CSRh) by measuring the activity of various promoter fragments in FGFR3-expressing (CFK2) and nonexpressing (RCJ) chondrocyte-like cell lines. Furthermore, we demonstrate that activation of PTH/PTHrP receptors, either by stimulation with PTH or through the introduction of activating mutations, represses CSRh-mediated transcriptional activity. Finally, the transcriptional repression of the CSRh element was mimicked by treatment with forskolin, 8-bromo-cAMP, and 3- isobutyl-1-methylxanthine or by overexpression of the catalytic SUBunit of protein kinase A. Together, these data suggest that protein kinase A activity is a critical factor that regulates fgfr3 gene expression in the proliferative or prehypertrophic compartment of the epiphyseal growth plate. Furthermore, these results provide a possible link between PTHrP signaling and fgfr3 gene expression during the process of endochondral ossification.
AB - Signaling through fibroblast growth factor receptors (FGFRs) is critical for the development and patterning of the vertebrate skeleton. Gain-of- function alleles of fgfr2 and fgfr3 have been linked to several dominant skeletal disorders in humans, while null mutations in fgfr3 result in the overgrowth of long bones in a mouse model system. Interestingly, the expression pattern of fgfr3 in growth plate chondrocytes overlaps that of the parathyroid hormone (PTH)-related peptide (PTHrP) receptor, a signaling molecule that also regulates endochondral ossification. The coincident expression of these two receptors suggests that their signaling pathways may also interact. To gain insight into the regulatory mechanism(s) that govern the expression of the fgfr3 gene in chondrocytes, we have identified a cell- specific transcriptional regulatory element (CSRh) by measuring the activity of various promoter fragments in FGFR3-expressing (CFK2) and nonexpressing (RCJ) chondrocyte-like cell lines. Furthermore, we demonstrate that activation of PTH/PTHrP receptors, either by stimulation with PTH or through the introduction of activating mutations, represses CSRh-mediated transcriptional activity. Finally, the transcriptional repression of the CSRh element was mimicked by treatment with forskolin, 8-bromo-cAMP, and 3- isobutyl-1-methylxanthine or by overexpression of the catalytic SUBunit of protein kinase A. Together, these data suggest that protein kinase A activity is a critical factor that regulates fgfr3 gene expression in the proliferative or prehypertrophic compartment of the epiphyseal growth plate. Furthermore, these results provide a possible link between PTHrP signaling and fgfr3 gene expression during the process of endochondral ossification.
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U2 - 10.1074/jbc.274.43.30934
DO - 10.1074/jbc.274.43.30934
M3 - Article
C2 - 10521488
AN - SCOPUS:0032695795
SN - 0021-9258
VL - 274
SP - 30934
EP - 30942
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 43
ER -