Tel1p preferentially associates with short telomeres to stimulate their elongation.
In many organisms, telomeric DNA consists of long tracts of short repeats. Shorter tracts are preferentially lengthened by telomerase, suggesting a conserved mechanism that recognizes and elongates short telomeres. Tel1p, an ATM family checkpoint kinase, plays an important role in telomere elongation, as cells lacking Tel1p have short telomeres and show reduced recruitment of telomerase components to telomeres. We show that Tel1p association increased as telomeres shortened in vivo in the presence or absence of telomerase and that Tel1p preferentially associated with the shortest telomeres. Tel1p association was independent of Tel1p kinase activity and enhanced by Mre11p. Tel1p overexpression simultaneously stimulated telomerase-mediated elongation and Tel1p association with all telomeres. Thus, Tel1p preferentially associates with the shortest telomeres and stimulates their elongation by telomerase.
Hector
Ronald E
RE
Department of Molecular Genetics, Cleveland Clinic Lerner College of Medicine at Case Western Reserve University, Lerner Research Institute, 9500 Euclid Avenue, NE20, Cleveland, OH 44195, USA.
Shtofman
Rebecca L
RL
Ray
Alo
A
Chen
Bo-Ruei
BR
Nyun
Thihan
T
Berkner
Kathleen L
KL
Runge
Kurt W
KW
D016922:Cellular Senescence; D004706:Endodeoxyribonucleases / Q000378:metabolism; D005090:Exodeoxyribonucleases / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000032:analysis / Q000378:metabolism*; D008957:Models, Genetic; D017346:Protein Serine-Threonine Kinases / Q000032:analysis / Q000378:metabolism*; D011995:Recombination, Genetic; D029701:Saccharomyces cerevisiae Proteins / Q000032:analysis / Q000378:metabolism*; D016615:Telomere / Q000378:metabolism* / Q000648:ultrastructure