FIGURE 6.

hTERT-hTR RNP and telomerase activity do not significantly change over the cell cycle. A, HeLa ZZF-hTERT cells were synchronized at G₁/S phase by double thymidine block. The amount of hTR cross-linked to ZZF-hTERT was assayed via RT-qPCR. Bound hTR values were normalized to input GAPDH mRNA and set relative to t = 0 (n = 3). Input hTR normalized to input GAPDH was also invariant (not shown). Telomerase activity was measured by QTRAP, with values set relative to t = 0 (n = 3). B, HeLa ZZF-hTERT cells were synchronized at prometaphase using nocodazole following a single round of thymidine block and release. The amounts of hTERT-hTR RNP and telomerase activity were assayed as described in A (n = 3). The negative control sample (con) was the asynchronously dividing parental HeLa cells. async, asynchronous cell cultures; n.s., not significant.