RRC ID 49342
Author Tashiro S, Nishihara Y, Kugou K, Ohta K, Kanoh J.
Title Subtelomeres constitute a safeguard for gene expression and chromosome homeostasis.
Journal Nucleic Acids Res
Abstract The subtelomere, a telomere-adjacent chromosomal domain, contains species-specific homologous DNA sequences, in addition to various genes. However, the functions of subtelomeres, particularly subtelomeric homologous (SH) sequences, remain elusive. Here, we report the first comprehensive analyses of the cellular functions of SH sequences in the fission yeast, Schizosaccharomyces pombe. Complete removal of SH sequences from the genome revealed that they are dispensable for mitosis, meiosis and telomere length control. However, when telomeres are lost, SH sequences prevent deleterious inter-chromosomal end fusion by facilitating intra-chromosomal circularization. Surprisingly, SH-deleted cells sometimes survive telomere loss through inter-chromosomal end fusions via homologous loci such as LTRs, accompanied by centromere inactivation of either chromosome. Moreover, SH sequences function as a buffer region against the spreading of subtelomeric heterochromatin into the neighboring gene-rich regions. Furthermore, we found a nucleosome-free region at the subtelomeric border, which may be a second barrier that blocks heterochromatin spreading into the subtelomere-adjacent euchromatin. Thus, our results demonstrate multiple defense functions of subtelomeres in chromosome homeostasis and gene expression.
Volume 45(18)
Pages 10333-10349
Published 2017-10-13
DOI 10.1093/nar/gkx780
PII 4128830
PMID 28981863
PMC PMC5737222
MeSH Centromere / metabolism Chromosomal Instability / genetics Chromosomes, Fungal / physiology* Gene Expression* Gene Expression Regulation, Fungal Heterochromatin / metabolism Homeostasis / genetics* Organisms, Genetically Modified Schizosaccharomyces / genetics* Schizosaccharomyces pombe Proteins / genetics* Sequence Deletion Telomere / physiology* Telomere-Binding Proteins / metabolism
IF 11.147
Times Cited 13
Yeast NBRP S. pombe strains FY21204