Phosphorylation of GSK-3beta by cGMP-dependent protein kinase II promotes hypertrophic differentiation of murine chondrocytes.

Abstract

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.

• Authors: Yosuke Kawasaki, Fumitaka Kugimiya, Hirotaka Chikuda, Satoru Kamekura, Toshiyuki Ikeda, Naohiro Kawamura, Taku Saito, Yusuke Shinoda, Akiro Higashikawa, Fumiko Yano, Toru Ogasawara, Naoshi Ogata, Kazuto Hoshi, Franz Hofmann, James R Woodgett, Kozo Nakamura, Ung-il Chung, Hiroshi Kawaguchi
• Journal: The Journal of clinical investigation (J Clin Invest) Vol. 118 Issue 7 Pg. 2506-15 (Jul 2008) ISSN: 0021-9738 [Print] United States
• PMID: 18551195 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Axin Protein
• Collagen Type X
• High Mobility Group Proteins
• Repressor Proteins
• SOX9 Transcription Factor
• SOX9 protein, human
• Sox9 protein, mouse
• Transcription Factors
• beta Catenin
• GSK3B protein, human
• Glycogen Synthase Kinase 3 beta
• Gsk3b protein, mouse
• Cyclic GMP-Dependent Protein Kinase Type II
• Cyclic GMP-Dependent Protein Kinases
• PRKG2 protein, human
• Prkg2 protein, mouse
• Glycogen Synthase Kinase 3
• Alkaline Phosphatase
• Matrix Metalloproteinase 13
• Lithium Chloride

Topics

• Alkaline Phosphatase (genetics)
• Animals
• Axin Protein
• Cell Differentiation
• Cell Line
• Cells, Cultured
• Chondrocytes (cytology, metabolism)
• Collagen Type X (genetics, metabolism)
• Cyclic GMP-Dependent Protein Kinase Type II
• Cyclic GMP-Dependent Protein Kinases (genetics, metabolism)
• Gene Expression (drug effects)
• Glycogen Synthase Kinase 3 (deficiency, genetics, metabolism)
• Glycogen Synthase Kinase 3 beta
• Growth Plate (abnormalities, metabolism)
• HeLa Cells
• High Mobility Group Proteins (genetics, metabolism)
• Humans
• Lithium Chloride (pharmacology)
• Matrix Metalloproteinase 13 (genetics)
• Mice
• Mice, Inbred C57BL
• Mice, Knockout
• Mice, Transgenic
• Models, Biological
• Phosphorylation
• Repressor Proteins (genetics, metabolism)
• SOX9 Transcription Factor
• Signal Transduction (drug effects)
• Transcription Factors (genetics, metabolism)
• beta Catenin (metabolism)