Saccharomyces forkhead protein Fkh1 regulates donor preference during mating-type switching through the recombination enhancer.
Saccharomyces mating-type switching results from replacement by gene conversion of the MAT locus with sequences copied from one of two unexpressed donor loci, HML or HMR. MATa cells recombine with HMLalpha approximately 90% of the time, whereas MATalpha cells choose HMRa 80%-90% of the time. HML preference in MATa is controlled by the cis-acting recombination enhancer (RE) that regulates recombination along the entire left arm of chromosome III. Comparison of RE sequences between S. cerevisiae, S. carlsbergensis, and S. bayanus defines four highly conserved regions (A, B, C, and D) within a 270-bp minimum RE. An adjacent E region enhances RE activity. Multimers of region A, D, or E are sufficient to promote selective use of HML. Regions A, D, and E each bind in vivo the transcription activator forkhead proteins Fkh1p and Fkh2p and their associated Ndd1p, although there are no adjacent open reading frames (ORFs). Deletion of FKH1 significantly reduces MATa's use of HML, as does mutation of the Fkh1/Fkh2-binding sites in a multimer of region A. We conclude that Fkh1p regulates MATa donor preference through direct interaction with RE.
Rosenstiel Center and Department of Biology, Brandeis University, Waltham, Massachusetts 02254-9910, USA.
Kaiming
K
Sun
Eric
E
Coïc
Zhiqi
Z
Zhou
Pascal
P
Durrens
James E
JE
Haber
D000483:Alleles; D001483:Base Sequence; D001665:Binding Sites; D018797:Cell Cycle Proteins / Q000378:metabolism; D002843:Chromatin / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D051858:Forkhead Transcription Factors; D017353:Gene Deletion; D005800:Genes, Fungal; D049770:Genes, Mating Type, Fungal; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation; D016366:Open Reading Frames; D011233:Precipitin Tests; D011995:Recombination, Genetic; D012440:Saccharomyces / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism / Q000502:physiology*; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014157:Transcription Factors; D020798:Two-Hybrid System Techniques
D018797:Cell Cycle Proteins; D002843:Chromatin; C464906:Fkh1 protein, S cerevisiae; C464958:Fkh2 protein, S cerevisiae; D051858:Forkhead Transcription Factors; C118820:NDD1 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D004247:DNA