The double-stranded DNA-binding proteins TEBP-1 and TEBP-2 form a telomeric complex with POT-1

• Published in: Nature communications Vol. 12; no. 1; p. 2668
• Main Authors: Dietz, Sabrina, Almeida, Miguel Vasconcelos, Nischwitz, Emily, Schreier, Jan, Viceconte, Nikenza, Fradera-Sola, Albert, Renz, Christian, Ceron-Noriega, Alejandro, Ulrich, Helle D., Kappei, Dennis, Ketting, René F., Butter, Falk
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11-05-2021; Nature Publishing Group; Nature Portfolio
• Subjects: 14/19; 14/32; 14/63; 38/23; 38/35; 38/70; 631/45/475; 631/80/103/560; 64/11; 82/111; 82/58; 82/80; 82/83; Animals; Animals, Genetically Modified; Base Sequence; Binding; Binding Sites - genetics; Caenorhabditis elegans - genetics; Caenorhabditis elegans - metabolism; Caenorhabditis elegans Proteins - classification; Caenorhabditis elegans Proteins - genetics; Caenorhabditis elegans Proteins - metabolism; Chromosomes; Deoxyribonucleic acid; DNA; DNA - genetics; DNA - metabolism; DNA damage; DNA-binding protein; DNA-Binding Proteins - genetics; DNA-Binding Proteins - metabolism; Embryogenesis; Embryonic growth stage; Fertility; Germ Cells - metabolism; Homeostasis; Humanities and Social Sciences; Meiosis; Microscopy, Fluorescence - methods; multidisciplinary; Multiprotein Complexes - genetics; Multiprotein Complexes - metabolism; Mutants; Mutation; Nematodes; Phenotypes; Phylogeny; Protein Binding; Protein Isoforms - classification; Protein Isoforms - genetics; Protein Isoforms - metabolism; Proteins; Proteomics; Science; Science (multidisciplinary); Sterility; Telomerase; Telomere - genetics; Telomere - metabolism; Telomere-Binding Proteins - classification; Telomere-Binding Proteins - genetics; Telomere-Binding Proteins - metabolism; Telomeres; Worms; Yeast
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-22861-2

Telomeres are bound by dedicated proteins, which protect them from DNA damage and regulate telomere length homeostasis. In the nematode
Caenorhabditis elegans
, a comprehensive understanding of the proteins interacting with the telomere sequence is lacking. Here, we harnessed a quantitative proteomics approach to identify TEBP-1 and TEBP-2, two paralogs expressed in the germline and embryogenesis that associate to telomeres in vitro and in vivo.
tebp-1
and
tebp-2
mutants display strikingly distinct phenotypes:
tebp-1
mutants have longer telomeres than wild-type animals, while
tebp-2
mutants display shorter telomeres and a Mortal Germline. Notably,
tebp-1;tebp-2
double mutant animals have synthetic sterility, with germlines showing signs of severe mitotic and meiotic arrest. Furthermore, we show that POT-1 forms a telomeric complex with TEBP-1 and TEBP-2, which bridges TEBP-1/-2 with POT-2/MRT-1. These results provide insights into the composition and organization of a telomeric protein complex in
C. elegans
.
Telomeres, tandem repeats at the ends of linear chromosomes, have evolved to deal with the end replication and end protection. Using a proteomics approach, the authors identify TEBP-1 and TEBP-2, two double-stranded binding proteins which together are required for fertility. Despite being paralogs, they have distinct individual effects on telomere dynamics; TEBP-1 and TEBP-2 are part of a telomeric complex also containing POT-1.