MCB-mediated regulation of cell cycle-specific cdc22(+) transcription in fission yeast

Maqbool, Z., Kersey, P.J., Fantes, P.A. and McInerny, C.J. (2003) MCB-mediated regulation of cell cycle-specific cdc22(+) transcription in fission yeast. Molecular Genetics and Genomics, 269(6), pp. 765-775. (doi: 10.1007/s00438-003-0885-4)

Abstract

The cdc22+ gene of the fission yeast, Schizosaccharomyces pombe , encodes the large subunit of ribonucleotide reductase, and is periodically expressed during the mitotic cell cycle, transcript abundance reaching a maximum at the G1-S boundary. This regulation of expression is controlled by a transcription factor complex called DSC1, which binds to MCB motifs (ACGCGT) present in the promoter of <i>cdc22</i>⁺. <i>cdc22</i>⁺ has a complex pattern of MCBs, including two clusters of four motifs each, one of which is located within the transcribed region. We show that both clusters of MCBs contribute to the regulation of <i>cdc22</i>⁺ expression during the cell cycle, each having a different role. The MCB cluster within the transcribed region has the major role in regulating <i>cdc22</i>⁺, as its removal results in loss of transcription. The upstream cluster, instead, controls cell cycle-specific transcription through a negative function, as its removal results in expression of <i>cdc22</i>⁺ throughout the cell cycle. Both MCB clusters bind DSC1. We show that the interaction of DSC1 with the MCB cluster within the transcribed region has a high "on-off" rate, suggesting a mechanism by which DSC1 could activate expression, and still allow RNA polymerase to pass during transcription. Finally, we show that both clusters are orientation-dependent in their function. The significance of these results, in the context of MCB-mediated regulation of G1-S expression in fission yeast, is discussed.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: McInerny, Dr Chris
• Authors: Maqbool, Z., Kersey, P.J., Fantes, P.A., and McInerny, C.J.
• College/School: College of Medical Veterinary and Life Sciences > School of Life Sciences; College of Medical Veterinary and Life Sciences > School of Molecular Biosciences
• Journal Name: Molecular Genetics and Genomics
• Journal Abbr.: Mol. Genet. Genomics
• ISSN: 1617-4615
• ISSN (Online): 1617-4623
• Published Online: 30 July 2003