Human telomeres have different overhang sizes at leading versus lagging strands.
G-rich 3' telomeric overhangs are required both for forming the distinct telomere structures to protect chromosome ends and for extending telomeres by telomerase. However, little is known about the molecular mechanisms generating telomere overhangs in human cells. We show here that cultured normal human diploid cells have longer G overhangs at telomeres generated by lagging-strand synthesis than by leading-strand synthesis. We also demonstrate that telomerase expression results in elongated overhangs at the leading daughter telomeres. Thus, the overhangs at the leading and lagging daughter telomeres are generated differently in human cells, and telomerase may preferentially affect overhangs generated at the telomeres produced by leading-strand synthesis.
Chai
Weihang
W
Department of Cell Biology, The University of Texas Southwestern Medical Center at Dallas, 5323 Harry Hines Boulevard, Dallas, Texas 75390, USA.
Du
Qun
Q
Shay
Jerry W
JW
Wright
Woodring E
WE
D002460:Cell Line; D004261:DNA Replication; D006801:Humans; D019098:Telomerase / Q000378:metabolism; D016615:Telomere / Q000737:chemistry* / Q000378:metabolism
D019098:Telomerase