Cell cycle-dependent regulation of the human aurora B promoter.

Aurora B is an important regulator of mitosis, and its mRNA and protein levels are tightly regulated during the cell cycle. In this study, we cloned the 5' flanking region of the human aurora B gene and characterized its promoter activity. Two major transcription initiation sites were identified by primer extension. aurora B promoter activity was upregulated during M phase, and its cell cycle-dependent element (CDE) and cell cycle-gene homology region (CHR) upstream of the transcription initiation sites regulated the cell cycle-dependent promoter activity. Several CDE-binding protein complexes were identified using the electrophoretic mobility shift assay. Using the biotin-streptavidin pull-down assay, binding of E2F-1, E2F-4, and DP-2, but not of DP-1, to the CDE was detected. These results demonstrate that aurora B mRNA level is regulated by CDE-CHR and that a subset of E2F/DP family proteins binds to the CDE.