Daughter-specific repression of Saccharomyces cerevisiae HO: Ash1 is the commander.
The GATA-1-like factor Ash1 is a repressor of the HO gene, which encodes an endonuclease that is responsible for mating-type switching in the yeast Saccharomyces cerevisiae. A multi-step programme, which involves a macromolecular protein complex, the secondary structure of ASH1 mRNA and the cell cytoskeleton, enables Ash1 to asymmetrically localize to the daughter cell nucleus in late anaphase and to repress HO transcription. The resulting Ash1 activity prevents the daughter cell from switching mating type. How does Ash1 inhibit transcription of HO exclusively in the daughter cell? In this review, a speculative model is proposed and discussed. Through its action as a daughter-specific repressor, Ash1 can be considered to be an ancestral regulator of cell fate in eukaryotes.
Telethon Institute of Genetics and Medicine, Via P. Castellino 111, 80131 Naples, Italy. cosma@tigem.it
Maria Pia
MP
Cosma
D003599:Cytoskeleton / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D015252:Deoxyribonucleases, Type II Site-Specific / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*
C098733:ASH1 protein, S cerevisiae; D004268:DNA-Binding Proteins; D012333:RNA, Messenger; D012097:Repressor Proteins; D012261:Ribonucleoproteins; D029701:Saccharomyces cerevisiae Proteins; C530845:HO protein, S cerevisiae; C037725:SCEI protein, S cerevisiae; D015252:Deoxyribonucleases, Type II Site-Specific