Figure 5.

Transcript levels of mouse and human UMP1 increase after IFN-γ stimulation. Northern blot analysis of UMP1 transcripts in total RNA from mouse embryonic stem cells (A) and human HeLa cells (B) treated with 1,000 units/ml IFN-γ for 24 h where indicated. Membranes were hybridized with radiolabeled probes, stripped, and rehybridized as described in Materials and Methods. Quantification of signals revealed a 2-fold induction of mUMP1 transcript and a 2.1-fold induction of hUMP1. Transcript levels of β5i/LMP7, an immunoproteasome-specific subunit, increased by a factor of 85, whereas those of β6, encoding a subunit present in both standard and immunoproteasome, remained unchanged after IFN-γ treatment.