Phosphorylation of GSK-3beta by cGMP-dependent protein kinase II promotes hypertrophic differentiation of murine chondrocytes.
cGMP-dependent protein kinase II (cGKII; encoded by PRKG2) is a serine/threonine kinase that is critical for skeletal growth in mammals; in mice, cGKII deficiency results in dwarfism. Using radiographic analysis, we determined that this growth defect was a consequence of an elongated growth plate and impaired chondrocyte hypertrophy. To investigate the mechanism of cGKII-mediated chondrocyte hypertrophy, we performed a kinase substrate array and identified glycogen synthase kinase-3beta (GSK-3beta; encoded by Gsk3b) as a principal phosphorylation target of cGKII. In cultured mouse chondrocytes, phosphorylation-mediated inhibition of GSK-3beta was associated with enhanced hypertrophic differentiation. Furthermore, cGKII induction of chondrocyte hypertrophy was suppressed by cotransfection with a phosphorylation-deficient mutant of GSK-3beta. Analyses of mice with compound deficiencies in both protein kinases (Prkg2(-/-)Gsk3b(+/-)) demonstrated that the growth retardation and elongated growth plate associated with cGKII deficiency were partially rescued by haploinsufficiency of Gsk3b. We found that beta-catenin levels decreased in Prkg2(-/-) mice, while overexpression of cGKII increased the accumulation and transactivation function of beta-catenin in mouse chondroprogenitor ATDC5 cells. This effect was blocked by coexpression of phosphorylation-deficient GSK-3beta. These data indicate that hypertrophic differentiation of growth plate chondrocytes during skeletal growth is promoted by phosphorylation and inactivation of GSK-3beta by cGKII.
Sensory and Motor System Medicine, Faculty of Medicine, University of Tokyo, Tokyo, Japan.
Yosuke
Y
Kawasaki
Fumitaka
F
Kugimiya
Hirotaka
H
Chikuda
Satoru
S
Kamekura
Toshiyuki
T
Ikeda
Naohiro
N
Kawamura
Taku
T
Saito
Yusuke
Y
Shinoda
Akiro
A
Higashikawa
Fumiko
F
Yano
Toru
T
Ogasawara
Naoshi
N
Ogata
Kazuto
K
Hoshi
Franz
F
Hofmann
James R
JR
Woodgett
Kozo
K
Nakamura
Ung-il
UI
Chung
Hiroshi
H
Kawaguchi
D000469:Alkaline Phosphatase / Q000235:genetics; D000818:Animals; D060466:Axin Protein; D002454:Cell Differentiation; D002460:Cell Line; D002478:Cells, Cultured; D019902:Chondrocytes / Q000166:cytology* / Q000378:metabolism; D024121:Collagen Type X / Q000235:genetics / Q000378:metabolism; D062967:Cyclic GMP-Dependent Protein Kinase Type II; D017869:Cyclic GMP-Dependent Protein Kinases / Q000235:genetics / Q000378:metabolism*; D015870:Gene Expression / Q000187:drug effects; D038362:Glycogen Synthase Kinase 3 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D000071679:Glycogen Synthase Kinase 3 beta; D006132:Growth Plate / Q000002:abnormalities / Q000378:metabolism; D006367:HeLa Cells; D006609:High Mobility Group Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D018021:Lithium Chloride / Q000494:pharmacology; D053509:Matrix Metalloproteinase 13 / Q000235:genetics; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D008954:Models, Biological; D010766:Phosphorylation; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism; D055758:SOX9 Transcription Factor; D015398:Signal Transduction / Q000187:drug effects; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D051176:beta Catenin / Q000378:metabolism
D060466:Axin Protein; D024121:Collagen Type X; D006609:High Mobility Group Proteins; D012097:Repressor Proteins; D055758:SOX9 Transcription Factor; C527932:SOX9 protein, human; C527933:Sox9 protein, mouse; D014157:Transcription Factors; D051176:beta Catenin; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605507:Gsk3b protein, mouse; D062967:Cyclic GMP-Dependent Protein Kinase Type II; D017869:Cyclic GMP-Dependent Protein Kinases; C569729:PRKG2 protein, human; C569730:Prkg2 protein, mouse; D038362:Glycogen Synthase Kinase 3; D000469:Alkaline Phosphatase; D053509:Matrix Metalloproteinase 13; D018021:Lithium Chloride