The yeast SWI4 protein contains a motif present in developmental regulators and is part of a complex involved in cell-cycle-dependent transcription.
Transcription of the HO gene of Saccharomyces cerevisiae, which encodes a site-specific endonuclease that initiates cell-type switching (reviewed in refs. 1,2), is restricted to a short window of the cell cycle in late G1 (refs 3,4). A repeated element in the upstream region of HO (the cell-cycle box, CCB) and two regulatory proteins, SWI4 and SWI6, are required for cell-cycle-dependent expression of HO. Biochemical experiments have identified a factor, CCBF (cell-cycle box factor), that binds to the CCB elements and that presumably plays a key part in cell-cycle regulation of HO. The SWI4 and SWI6 genes are required for formation of the CCBF-DNA complex. Here we report the nucleotide sequence of the SWI4 gene and show that it contains two copies of the conserved SWI6-cdc10 motif observed in SWI6 of budding yeast, the Schizosaccharomyces pombe cdc10 gene required for progression through G19, the Drosophila Notch gene, and in the Caenorhabditis elegans lin-12 and glp-1 genes. We demonstrate by using antibodies to the SWI4 protein in gel-shift assays that the protein is present in the CCBF-DNA complex.
Andrews
B J
BJ
Department of Biochemistry and Biophysics, University of California, San Francisco 94143.
Herskowitz
I
I
D000595:Amino Acid Sequence; D001483:Base Sequence; D002453:Cell Cycle; D004268:DNA-Binding Proteins / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics*; D015966:Gene Expression Regulation, Fungal; D007158:Immunologic Techniques; D046911:Macromolecular Substances; D008969:Molecular Sequence Data; D012045:Regulatory Sequences, Nucleic Acid; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors / Q000235:genetics*; D014158:Transcription, Genetic
D004268:DNA-Binding Proteins; D005656:Fungal Proteins; D046911:Macromolecular Substances; C062214:SWI4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors