Daughter-specific repression of Saccharomyces cerevisiae HO: Ash1 is the commander.
نویسنده
چکیده
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.
منابع مشابه
A new yeast PUF family protein, Puf6p, represses ASH1 mRNA translation and is required for its localization.
In yeast Saccharomyces cerevisiae, Ash1p, a protein determinant for mating-type switching, is segregated within the daughter cell nucleus to establish asymmetry of HO expression. The accumulation of Ash1p results from ASH1 mRNA that is sorted as a ribonucleoprotein particle (mRNP or locasome) to the distal tip of the bud where translation occurs. To study the mechanism regulating ASH1 mRNA tran...
متن کاملIdentification of an Asymmetrically Localized Determinant, Ash1p, Required for Lineage-Specific Transcription of the Yeast HO Gene
S. cerevisiae cells exhibit asymmetric determination of cell fate. Cell division yields a mother cell, which is competent to transcribe the HO gene and switch mating type, and a daughter cell, which is not. We have isolated a mutant in which daughters transcribe HO and switch mating type. This mutation defines the ASH1 gene (asymmetric synthesis of HO). Deletion and overexpression of ASH1 cause...
متن کاملThe Khd1 protein, which has three KH RNA-binding motifs, is required for proper localization of ASH1 mRNA in yeast.
RNA localization is a widespread mechanism for achieving localized protein synthesis. In Saccharomyces cerevisiae, Ash1 is a specific repressor of transcription that localizes asymmetrically to the daughter cell nucleus through the localization of ASH1 mRNA to the distal tip of the daughter cell. This localization depends on the actin cytoskeleton and five She proteins, one of which is a type V...
متن کاملMating type switching in yeast controlled by asymmetric localization of ASH1 mRNA.
Cell divisions that produce progeny differing in their patterns of gene expression are key to the development of multicellular organisms. In the budding yeast Saccharomyces cerevisiae, mother cells but not daughter cells can switch mating type because they selectively express the HO endonuclease gene. This asymmetry is due to the preferential accumulation of an unstable transcriptional represso...
متن کاملDaughter-Specific Transcription Factors Regulate Cell Size Control in Budding Yeast
In budding yeast, asymmetric cell division yields a larger mother and a smaller daughter cell, which transcribe different genes due to the daughter-specific transcription factors Ace2 and Ash1. Cell size control at the Start checkpoint has long been considered to be a main regulator of the length of the G1 phase of the cell cycle, resulting in longer G1 in the smaller daughter cells. Our recent...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- EMBO reports
دوره 5 10 شماره
صفحات -
تاریخ انتشار 2004