A CDE/CHR tandem element regulates cell cycle-dependent repression of cyclin B2 transcription

Cyclin B is an important regulator of progression through the cell division cycle. The oscillating appearance of cyclin B1 and BZ proteins during the cell cycle is in part due to fluctuating mRNA levels. We had identified ear lier a tandem promoter element named cell cycle-dependent element (CDE) and cell cycle genes homology region (CHR) which regulates cell cycle-dependen t transcription of cdc25C, cyclin A and cdc2. Here we describe that cyclin BZ transcription is repressed through a novel CDE/CHR clement in resting an d G(1) cells. By relief of this repression in S and G(2) oscillating expres sion of cyclin B2 mRNA is achieved during the cell cycle. (C) 2000 Federati on of European Biochemical Societies. Published by Elsevier Science B.V. Al l rights reserved.