An Odd Pair Important For Cartilage Formation: Sox9 And P54nrb

Main Category: Bones / Orthopaedics
Also Included In: Biology / Biochemistry
Article Date: 04 Aug 2008 - 0:00 PDT

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New data, generated in mice by Riko Nishimura and colleagues, at Osaka University Graduate School of Dentistry, Japan, have provided insight into the formation of cartilage, a process that is known as chondrogenesis and that is an important event in bone development.

Previous studies have indicated an essential role for the protein Sox9 in promoting chondrogenesis. In this study, the authors screened a mouse chondrogenic cell line to identify proteins that interacted with Sox9 to activate the expression of a gene important for chondrogenesis, Col2a1.

A protein known as p54nrb was found to physically interact with Sox9 in cellular compartments known as nuclear paraspeckle bodies and to enhance expression of Col2a1. If the chondrogenic cell line was engineered to express a mutant form of p54nrb, the nuclear paraspeckle bodies had markedly altered appearance, and if precursor cells were engineered to express this mutant they could not develop into chondrocytes.

Further, mice engineered to express the same mutant protein exhibited dwarfism, indicating that p54nrb has an important role in regulating the function of Sox9 during chondrogenesis.

"Paraspeckle protein p54nrb links Sox9-mediated transcription with RNA processing during chondrogenesis in mice"
Kenji Hata, Riko Nishimura, Shuji Muramatsu, Akio Matsuda, Takuma Matsubara, Katsuhiko Amano, Fumiyo Ikeda, Vincent R. Harley and Toshiyuki Yoneda
J. Clin. Invest. doi:10.1172/JCI31373
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The Journal of Clinical Investigation (JCI) is the publication of the American Society for Clinical Investigation, an honor society of physician-scientists.

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