Contribution of CDP/Cux, a transcription factor, to cell cycle progression.
CCAAT-displacement protein/Cut homeobox (CDP/Cux) was initially identified as a transcriptional repressor. However, a number of studies have now suggested that CDP/Cux is a transcriptional activator as well. Stable DNA binding activity of CDP/Cux is up-regulated at the G(1)/S transition by two mechanisms, dephosphorylation by the Cdc25A phosphatase and proteolytic processing to generate a 110 kDa amino-truncated isoform, CDP/Cux p110. The generation of CDP/Cux p110 stimulates the expression of reporter plasmid containing the promoter sequences of some S phase-specific-genes such as DNA polymerase a gene, dihydrofolate reductase gene, carbamoyl-phosphate synthase/aspartate carbamoyl-transferase/dihydroorotase gene, and cyclin A gene. However, DNA binding activity of CDP/Cux is down-regulated at G(2) phase through a binding of cyclin A-cyclin-dependent kinases1 (Cdk1) to CDP/Cux. Furthermore, another CDP/Cux isoform, CDP/Cux p75, has been found to be associated with breast tumors indicating this isoform is involved in the abnormal proliferation of tumor cells. The differences in DNA binding of CDP/Cux isoforms in S and G(2) phases suggest important roles of CDP/Cux in cell cycle progression. In this review, we discuss the functions of CDP/Cux with a focus on its roles in cell cycle regulation and its possible potency leading to the cell cycle reentry of neurons.
Department of Pharmacology, Soochow University School of Medicine, Suzhou 215123, China.
Xifeng
X
Fei
Zhenghong
Z
Qin
Zhongqin
Z
Liang
D000818:Animals; D023081:CCAAT-Binding Factor / Q000378:metabolism*; D002453:Cell Cycle / Q000502:physiology*; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D015398:Signal Transduction / Q000502:physiology*; D015533:Transcriptional Activation / Q000502:physiology*
D023081:CCAAT-Binding Factor; D004268:DNA-Binding Proteins; D004247:DNA