These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Cell cycle-dependent regulation of the Skp2 promoter by GA-binding protein.
    Author: Imaki H, Nakayama K, Delehouzee S, Handa H, Kitagawa M, Kamura T, Nakayama KI.
    Journal: Cancer Res; 2003 Aug 01; 63(15):4607-13. PubMed ID: 12907639.
    Abstract:
    Skp2 is the F-box protein component of an SCF-type ubiquitin ligase that interacts specifically with p27(Kip1) and thereby promotes its ubiquitylation and degradation. The abundance of Skp2 mRNA oscillates in a cell cycle-dependent manner, being maximal in S and G(2) phases. The regulation of Skp2 transcription was investigated by cloning the promoter region of the mouse gene and determination of its activity in a luciferase reporter assay. Deletion analysis identified a minimal approximately 0.3-kb promoter region with marked transcriptional activity and a 105-bp essential sequence within this region. Electrophoretic mobility shift assays indicated the presence in nuclear extracts of proteins that bind to this sequence. Site-directed mutagenesis revealed that the core binding motif, CACTTCCG, which is similar to that of GA-binding protein (GABP), is essential for Skp2 transcription. "Supershift" analysis indicated that the protein-probe complexes detected by electrophoretic mobility shift assays contain GABP. Endogenous GABP bound to Skp2 promoter element in a cell cycle-dependent manner. Furthermore, overexpression of GABPbeta increased Skp2 promoter activity, and suppression of GABPalpha or GABPbeta by a small interfering RNA resulted in the reduction of Skp2 promoter activity. These data suggest that the cell cycle-dependent binding of GABP to the Skp2 promoter plays an important role in the regulation of Skp2 expression and cell cycle progression from G(1) to S phase.
    [Abstract] [Full Text] [Related] [New Search]