GEOapplication/xmlftp://ftp.ncbi.nlm.nih.gov/geo/series/GSE301nnn/GSE301562/primaryOK200OtherNeurospora crassaOtherhttps://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE301562GEOGSEfalseThe shelterin subunit TRF-1 mediates PRC2 function at ectopic telomere repeats in Neurospora crassa [HiC]Telomeres are crucial for maintaining chromosomal integrity and are characterized by repetitive sequences, which may be stabilized by the shelterin protein complex and/or by formation of secondary structures, such as G-quadruplexes (G4 DNA). Frequently, subtelomeric regions are decorated with di- and tri-methylated lysine 27 on histone H3 (H3K27me), repressive marks associated with facultative heterochromatin in many eukaryotes. Our previous work with the filamentous fungus Neurospora crassa demonstrated that native telomere repeats induce H3K27me at ectopic loci. Here we report investigations into the mechanism of this and demonstrate that nonnative telomere repeats can also induce H3K27me. Chromatin immunoprecipitation (ChIP) experiments with an anti-G4-DNA antibody showed that establishment of H3K27me does not depend on the formation of G4 DNA. Other ChIP experiments demonstrated binding of the shelterin member TRF-1 to interstitial telomere repeats that induce H3K27me but not to similar sequences that do not. Tethering experiments revealed that TRF-1, but not other proteins tested, is sufficient to induce H3K27me. Hi-C analyses demonstrated that ectopic telomeric repeats can interact with native telomeres. Together these results suggest that the shelterin complex plays a crucial role in establishment of H3K27me and repression at telomere sequences.2026/03/30GSE301562GSM9085290GSM908528920660301562Neurospora crassa[41700018]