Prevention of CCAAT/enhancer-binding protein beta DNA binding by hypoxia during adipogenesis.

ABSTRACT: Upon exposure to adipogenesis-inducing hormones, confluent 3T3-L1 preadipocytes express C/EBPbeta (CCAAT/enhancer binding protein beta). Early induced C/EBPbeta is inactive but, after a lag period, acquires its DNA-binding capability by sequential phosphorylation. During this period, preadipocytes pass the G(1)/S checkpoint synchronously. Thr(188) of C/EBPbeta is phosphorylated initially to prime the factor for subsequent phosphorylation at Ser(184) or Thr(179) by GSK3beta, which translocates into the nuclei during the G(1)/S transition. Many events take place during the G(1)/S transition, including reduction in p27(Kip1) protein levels, retinoblastoma (Rb) phosphorylation, GSK3beta nuclear translocation, and C/EBPbeta binding to target promoters. During hypoxia, hypoxia-inducible factor-1

SUBMITTER: Park YK 

PROVIDER: S-EPMC2823406 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature