Telomeres--Unsticky Ends

Cells are equipped with surveillance mechanisms that carefully scan the DNA for breaks and repair any that are found. So what happens when this quality control apparatus comes upon the end of the chromosome, the telomere? An ill-placed repair at this position will join two chromosomes together or, worse, join the end of one chromosome to internal sequences in another, creating genetic havoc. In his Perspective, Shore summarizes emerging evidence in yeast that Ku, a protein that facilitates the joining of broken DNA ends, may work in a special way at the telomere to actually protect the ends from inappropriate joining reactions and facilitate other telomere functions.