TRF1 SUMOylation is increased by NS and reduced by GNL3L. (A) The amount of SUMOylated TRF1 in the pull-down fraction (His PD) is increased by NS overexpression and decreased by GNL3L overexpression. (B) Conversely, NS-KD (shNS) decreases TRF1 SUMOylation, whereas GNL3L knockdown (shG3L) shows the opposite effect. (C) The coIP efficiency of TRF1 and MMS21 is reduced by GNL3L overexpression but not affected by NS overexpression.