The ETS protein MEF is regulated by phosphorylation-dependent proteolysis via the protein-ubiquitin ligase SCFSkp2.

MEF is an ETS-related transcription factor with strong transcriptional activating activity that affects hematopoietic stem cell behavior and is required for normal NK cell and NK T-cell development. The MEF (also known as ELF4) gene is repressed by several leukemia-associated fusion transcription factor proteins (PML-retinoic acid receptor alpha and AML1-ETO), ...
but it is also activated by retroviral insertion in several cancer models. We have previously shown that cyclin A-dependent phosphorylation of MEF largely restricts its activity to the G(1) phase of the cell cycle; we now show that MEF is a short-lived protein whose expression level also peaks during late G(1) phase. Mutagenesis studies show that the rapid turnover of MEF in S phase is dependent on the specific phosphorylation of threonine 643 and serine 648 at the C terminus of MEF by cdk2 and on the Skp1/Cul1/F-box (SCF) E3 ubiquitin ligase complex SCF(Skp2), which targets MEF for ubiquitination and proteolysis. Overexpression of MEF drives cells through the G(1)/S transition, thereby promoting cell proliferation. The tight regulation of MEF levels during the cell cycle contributes to its effects on regulating cell cycle entry and cell proliferation.
Mesh Terms:
Amino Acid Sequence, Cell Line, Cell Line, Tumor, Cysteine Proteinase Inhibitors, DNA-Binding Proteins, Gene Expression Regulation, Half-Life, Humans, Hydrolysis, Leupeptins, Ligases, Mutagenesis, Site-Directed, Phosphorylation, Proteins, Serine, Threonine, Transcription Factors, Ubiquitin
Mol. Cell. Biol.
Date: Apr. 01, 2006
Download Curated Data For This Publication
101574
Switch View:
  • Interactions 2
  • PTM Genes 1