Title: | Fission yeast Rap1 homolog is a telomere-specific silencing factor and interacts with Taz1p |
Author(s): | Park MJ; Jang YK; Choi ES; Kim HS; Park SD; |
Address: | "School of Biological Sciences, Seoul National University, Korea" |
ISSN/ISBN: | 1016-8478 (Print) 1016-8478 (Linking) |
Abstract: | "Taz1p is the fission yeast orthologue of human TRF2, a telomeric repeat-binding protein. Delta(taz1) mutants are defective in telomeric silencing, telomere length control, and meiotic recombination events. A recent report demonstrated that the human Rap1p homolog (hRap1) is recruited to telomere by interaction with TRF2, arguing that the telomere control mechanism of higher eukaryotes is distinct from that of the budding yeast. Taz1p showed a significant similarity to human TRF2, but not with the budding yeast Rap1p (scRap1p). This suggests that Taz1p and TRF2 share common features in telomere regulation. To assess the roles of Taz1p in telomere-related functions in detail, we attempted to identify a protein(s) that interacts with Taz1p by using two-hybrid screening. Interestingly, the sequence analysis of a positive clone revealed a perfect match with a Rap1 homolog in S. pombe (spRap1), which showed a significant homology with scRap1p and hRap1p. Here we show that the spRap1 deficiency in haploid cells is viable, which results in increased telomere length regulation, disruption of telomere silencing, and aberrant meiosis (like the delta(taz1) mutant). This suggests that spRap1p might be recruited to the telomere by Taz1p and play crucial roles in telomere function. Interestingly, the delta(rap1) mutants in fission yeast are defective only for telomere silencing. Therefore, the role of spRap1p may be distinct from that of scRap1p, which is involved in the silencing at both the telomere and mating type locus. Our data, therefore, suggest that the regulation mechanisms of telomere in fission yeast resemble that of higher eukaryotic cells rather than the budding yeast" |
Keywords: | Base Sequence DNA-Binding Proteins/genetics/metabolism *Gene Silencing Humans Molecular Sequence Data Schizosaccharomyces/chemistry/*genetics/metabolism Schizosaccharomyces pombe Proteins/chemistry/genetics/*metabolism Telomere/*metabolism Telomere-Bindin; |
Notes: | "MedlinePark, Min Jung Jang, Yeun Kyu Choi, Eun Shik Kim, Hyun Soo Park, Sang Dai eng Research Support, Non-U.S. Gov't Korea (South) 2002/05/23 Mol Cells. 2002 Apr 30; 13(2):327-33" |