Expression of mouse Fbxw7 isoforms is regulated in a cell cycle- or p53-dependent manner

Journal Article · Fri Nov 10 04:00:00 EST 2006 · Biochemical and Biophysical Research Communications

DOI:https://doi.org/10.1016/j.bbrc.2006.09.003· OSTI ID:20854562

Matsumoto, Akinobu ^[1]; Onoyama, Ichiro ^[1]; Nakayama, Keiichi I ^[2]

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1. Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582 (Japan)
2. Department of Molecular and Cellular Biology, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, Fukuoka 812-8582 (Japan) and CREST, Japan Science and Technology Agency, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan)

Fbxw7 is the F-box protein component of an SCF-type ubiquitin ligase that contributes to the ubiquitin-dependent degradation of cell cycle activators and oncoproteins. Three isoforms ({alpha}, {beta}, and {gamma}) of Fbxw7 are produced from mRNAs with distinct 5' exons. We have now investigated regulation of Fbxw7 expression in mouse tissues. Fbxw7{alpha} mRNA was present in all tissues examined, whereas Fbxw7{beta} mRNA was detected only in brain and testis, and Fbxw7{gamma} mRNA in heart and skeletal muscle. The amount of Fbxw7{alpha} mRNA was high during quiescence (G phase) in mouse embryonic fibroblasts (MEFs) and T cells, but it decreased markedly as these cells entered the cell cycle. The abundance of Fbxw7{alpha} mRNA was unaffected by cell irradiation or p53 status. In contrast, X-irradiation increased the amount of Fbxw7{beta} mRNA in wild-type MEFs but not in those from p53-deficient mice, suggesting that radiation-induced up-regulation of p53 leads to production of Fbxw7{beta} mRNA. Our results thus indicate that expression of Fbxw7 isoforms is differentially regulated in a cell cycle- or p53-dependent manner.

• OSTI ID: 20854562
• Journal Information: Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 1 Vol. 350; ISSN 0006-291X; ISSN BBRCA9
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
BRAIN
CELL CYCLE
EXONS
FIBROBLASTS
HEART
IRRADIATION
LIGASES
MICE
MUSCLES
NEOPLASMS