Conserved Telomere Maintenance Component 1 Interacts with STN1 and Maintains Chromosome Ends in Higher Eukaryotes

• DOI: 10.1016/j.molcel.2009.09.017
• Publication Date: 2009-10-23T09:15:31Z
• Authors: Yulia V. Surovtseva; Dmitri Churikov; Kara A. Boltz; Xiangyu Song; Jonathan C. Lamb; Ross Warrington; Katherine Leehy; Michelle Heacock; Carolyn M. Price; Dorothy E. Shippen
• Keywords: Recombination, Genetic; 0303 health sciences; Arabidopsis Proteins; Chromosomal Proteins, Non-Histone; Telomere-Binding Proteins; Arabidopsis; Cell Biology; Telomere; Chromosomes, Plant; Genomic Instability; 03 medical and health sciences; Eukaryotic Cells; Cell Line, Tumor; Mutation; Humans; Nucleic Acid Conformation; Anaphase; Molecular Biology; Conserved Sequence; In Situ Hybridization, Fluorescence; Protein Binding

Orthologs of the yeast telomere protein Stn1 are present in plants, but other components of the Cdc13/Stn1/Ten1 (CST) complex have only been found in fungi. Here we report the identification of conserved telomere maintenance component 1 (CTC1) in plants and vertebrates. CTC1 encodes an approximately 140 kDa telomere-associated protein predicted to contain multiple OB-fold domains. Arabidopsis mutants null for CTC1 display a severe telomere deprotection phenotype accompanied by a rapid onset of developmental defects and sterility. Telomeric and subtelomeric tracts are dramatically eroded, and chromosome ends exhibit increased G overhangs, recombination, and end-to-end fusions. AtCTC1 both physically and genetically interacts with AtSTN1. Depletion of human CTC1 by RNAi triggers a DNA damage response, chromatin bridges, increased G overhangs, and sporadic telomere loss. These data indicate that CTC1 participates in telomere maintenance in diverse species and that a CST-like complex is required for telomere integrity in multicellular organisms.