Separation-of-function mutants of yeast Ku80 reveal a Yku80p-Sir4p interaction involved in telomeric silencing
| Autor: | Andrew D. McAinsh, Bettina Meier, Rajat Roy, Heidi Feldmann, Stephen P. Jackson |
|---|---|
| Rok vydání: | 2003 |
| Předmět: |
Ku80
Saccharomyces cerevisiae Proteins Genotype DNA repair Saccharomyces cerevisiae Mutant Telomeric heterochromatin Biology Biochemistry Gene silencing Animals Humans Amino Acid Sequence Gene Silencing Molecular Biology Gene Ku Autoantigen Silent Information Regulator Proteins Saccharomyces cerevisiae DNA Primers Genetics Base Sequence Sequence Homology Amino Acid Mutagenesis DNA Helicases Antigens Nuclear Cell Biology Telomere biology.organism_classification Peptide Fragments Recombinant Proteins DNA-Binding Proteins Mutagenesis Site-Directed Sequence Alignment |
| Zdroj: | The Journal of biological chemistry. 279(1) |
| ISSN: | 0021-9258 |
| Popis: | The Saccharomyces cerevisiae Ku heterodimer comprising Yku70p and Yku80p is involved in telomere maintenance and DNA repair by the pathway of non-homologous end joining. It is also a key regulator of transcriptional silencing of genes placed in close proximity to telomeres. Here, we describe the identification of separation-of-function mutants of Yku80p that exhibit defects in silencing but not DNA repair and show that these mutations map to an evolutionarily conserved domain within Yku80p. Furthermore, we reveal that Yku80p interacts with the silent information regulator protein Sir4p and that this interaction is mediated by the N-terminal 200 amino acid residues of Sir4p. Notably, this interaction also requires the region of Yku80p that contains the sites of the silencing defective mutations. Finally, we show that these mutations impair the Yku80p-Sir4p interaction and recruitment of Sir3p to telomeric regions in vivo. Taken together with other data, these findings indicate that the Yku80p-Sir4p interaction plays a vital role in the assembly of telomeric heterochromatin. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|