Evidence for a new step in telomere maintenance.
The strand of telomeric DNA that runs 5'-3' toward a chromosome end is typically G rich. Telomerase-generated G tails are expected at one end of individual DNA molecules. Saccharomyces telomeres acquire TG1-3 tails late in S phase. Moreover, the telomeres of linear plasmids can interact when the TG1-3 tails are present. Molecules that mimic the structures predicted for telomere replication intermediates were generated in vitro. These in vitro generated molecules formed telomere-telomere interactions similar to those on molecules isolated from yeast, but only if both ends that interacted had a TG1-3 tail. Moreover, TG1-3 tails were generated in vivo in cells lacking telomerase. These data suggest a new step in telomere maintenance, cell cycle-regulated degradation of the C1-3A strand, which can generate a potential substrate for telomerase and telomere-binding proteins at every telomere.
Wellinger
R J
RJ
Department of Microbiology, Faculty of Medicine, Université de Sherbrooke, Quebec, Canada.
Ethier
K
K
Labrecque
P
P
Zakian
V A
VA
D001483:Base Sequence; D002412:Cations / Q000494:pharmacology; D002453:Cell Cycle / Q000235:genetics; D004261:DNA Replication / Q000235:genetics; D004271:DNA, Fungal / Q000235:genetics; D006358:Hot Temperature; D008274:Magnesium / Q000494:pharmacology; D008969:Molecular Sequence Data; D010957:Plasmids; D012331:RNA, Fungal / Q000235:genetics; D012091:Repetitive Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000201:enzymology / Q000235:genetics; D019098:Telomerase / Q000235:genetics; D016615:Telomere / Q000201:enzymology* / Q000235:genetics*
D002412:Cations; D004271:DNA, Fungal; D012331:RNA, Fungal; D019098:Telomerase; D008274:Magnesium