Cell cycle-regulated transcription in fission yeast: Cdc10-Res protein interactions during the cell cycle and domains required for regulated transcription.
In Schizosaccharomyces pombe the MBF (DSC1) complex mediates transcriptional activation at Start and is composed of a common subunit called Cdc10 in combination with two alternative DNA-binding partners, Res1 and Res2. It has been suggested that a high-activity MBF complex (at G1/S) is switched to a low-activity complex (in G2) by the incorporation of the negative regulatory subunit Res2. We have analyzed MBF protein-protein interactions and find that both Res proteins are associated with Cdc10 throughout the cell cycle, arguing against this model. Furthermore we demonstrate that Res2 is capable of interacting with a mutant form of Cdc10 that has high transcriptional activity. It has been shown previously that both Res proteins are required for periodic cell cycle-regulated transcription. Therefore a series of Res1-Res2 hybrid molecules was used to determine the domains that are specifically required to regulate periodic transcription. In Res2 the nature of the C-terminal region is critical, and in both Res1 and Res2, a domain overlapping the N-terminal ankyrin repeat and a recently identified activation domain is important for mediating cell cycle-regulated transcription.
Whitehall
S
S
School of Biochemistry and Genetics, The Medical School, The University of Newcastle, Newcastle-upon-Tyne NE2 4HH, United Kingdom.
Stacey
P
P
Dawson
K
K
Jones
N
N
D002453:Cell Cycle / Q000235:genetics*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism; D005656:Fungal Proteins / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D008938:Mitosis / Q000235:genetics; D009154:Mutation; D011485:Protein Binding; D012568:Schizosaccharomyces / Q000235:genetics*; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; D015533:Transcriptional Activation; D019895:Transposases / Q000378:metabolism*
D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D029702:Schizosaccharomyces pombe Proteins; D014157:Transcription Factors; C061178:cdc10 protein, S pombe; C087021:res2 protein, S pombe; D019895:Transposases