Identification of TTAGGG-binding proteins in Neurospora crassa, a fungus with vertebrate-like telomere repeats

BMC Genomics

Research Article

Dennis Kappei¹  Anja Freiwald²  Marion Scheibe²  Falk Butter²  Núria Casas-Vila² 

[1] Cancer Science Institute of Singapore, National University of Singapore, 14 Medical Drive, 117599, Singapore, Singapore;Quantitative Proteomics, Institute of Molecular Biology (IMB) gGmbH, Ackermannweg 4, 55128, Mainz, Germany;

关键词: Interactomics;    Mass spectrometry;    Telomere;    Telosome;    Evolution;   

DOI  :  10.1186/s12864-015-2158-0

 received in 2015-06-20, accepted in 2015-10-27,  发布年份 2015

来源: Springer

【 摘 要 】

BackgroundTo date, telomere research in fungi has mainly focused on Saccharomyces cerevisiae and Schizosaccharomyces pombe, despite the fact that both yeasts have degenerated telomeric repeats in contrast to the canonical TTAGGG motif found in vertebrates and also several other fungi.ResultsUsing label-free quantitative proteomics, we here investigate the telosome of Neurospora crassa, a fungus with canonical telomeric repeats. We show that at least six of the candidates detected in our screen are direct TTAGGG-repeat binding proteins. While three of the direct interactors (NCU03416 [ncTbf1], NCU01991 [ncTbf2] and NCU02182 [ncTay1]) feature the known myb/homeobox DNA interaction domain also found in the vertebrate telomeric factors, we additionally show that a zinc-finger protein (NCU07846) and two proteins without any annotated DNA-binding domain (NCU02644 and NCU05718) are also direct double-strand TTAGGG binders. We further find two single-strand binders (NCU02404 [ncGbp2] and NCU07735 [ncTcg1]).ConclusionBy quantitative label-free interactomics we identify TTAGGG-binding proteins in Neurospora crassa, suggesting candidates for telomeric factors that are supported by phylogenomic comparison with yeast species. Intriguingly, homologs in yeast species with degenerated telomeric repeats are also TTAGGG-binding proteins, e.g. in S. cerevisiae Tbf1 recognizes the TTAGGG motif found in its subtelomeres. However, there is also a subset of proteins that is not conserved. While a rudimentary core TTAGGG-recognition machinery may be conserved across yeast species, our data suggests Neurospora as an emerging model organism with unique features.

【 授权许可】

CC BY   
© Casas-Vila et al. 2015