Cell-cycle-dependent expression of HOGG1 gene
The cell-cycle-dependent expression of HOGG1 was followed by northern blot hybridization of poly(A)+ RNA isolated from synchronized HaCat cells. Progression throughout the cell cycle was monitored by [3H]thymidine incorporation, which started to increase 12 h after serum addition and reached a peak at 25 h (Figure 1A). Northern blots revealed two mRNA bands of ∼2.0 and 2.4 kb, representing the transcripts of the nuclear and mitochondrial isoforms, respectively (Figure 1B). Expression of both isoforms increased during S-phase and into G2.