Figure 7. GLE, DPE-L1, and DPE-L2 function differently in TAF1-dependent transcription and TAF1-independent CIITA-mediated transcription.

The transcriptional activity regulated by DPE-L1 and DPE-L2 (Left panel) and GLE (Right panel) depend on a functional TAF1. tsBN462 cells were co-transfected at the permissive temperature (32°C)with a CIITA-expression or control vector (which are not TAF1-dependent) and either wild type (WT+32), DPE-L1, DPE-L2 or GLE constructs. All constructs shared common 5′ and 3′ termini at −416 and +32, respectively. After 24 hours, cells were either shifted to the non-permissive temperature (39°C) or left at 32°C for an additional 24 hours prior to harvesting. Promoter activity was assessed by CAT activity as described in Materials and Methods. The results are the representative of two separate sets of independent experiments, each done with independent duplicate transfections. (*) and (**) denote significant differences between the activities of mutant constructs relative to the wild type at 32°C or 39°C with CIITA, respectively.