Figure 6.SIRT6 promotes resolution of DNA double strand breaks (DSBs).(a-c) Impaired resolution of DSBs in SIRT6
knock-down (S6KD2) cells. Control (pSR) and knock-down (S6KD) cells were
isolated 1 hour after NCS treatment and tail moment was determined in
comet assays. (a) Histogram of tail moments of >100 cells. (b)
Representative comet images from S6KD or control cells following DNA damage
(+NCS) or mock (-NCS) treatment. (c) Mean tail moment of comet
assays shown in (a). Error bars indicate the S.E.M. (d)
Wild-type SIRT6 (S6WT), but not the mutant SIRT6 (S6HY), protein rescues
the DSB repair defect of SIRT6 knock-down cells. Mean tail moment of comet
assays for the indicated cells, following treatment with NCS and quantified
as in (c). (e) Resolution of site-specific DNA DSBs in SIRT6 KD (S6KD2) and
control (pSR) cells assayed using the I-SceI and I-PpoI systems.
Quantitative real-time PCR amplification of DNA using primers flanking the
DSB sites is shown. *, p=0.009; **, p=0.02. The data represent the average
of triplicate experiments, and error bars indicate the S.E.M.
