Human Pso4 is a metnase (SETMAR)-binding partner that regulates metnase function in DNA repair.

Metnase, also known as SETMAR, is a SET and transposase fusion protein with an undefined role in mammalian DNA repair. The SET domain is responsible for histone lysine methyltransferase activity at histone 3 K4 and K36, whereas the transposase domain possesses 5'-terminal inverted repeat (TIR)-specific DNA binding, DNA looping, and DNA cleavage activities. Although the transposase domain is essential for Metnase function in DNA repair, it is not clear how a protein with sequence-specific DNA binding activity plays a role in DNA repair.

Biochemical characterization of a SET and transposase fusion protein, Metnase: its DNA binding and DNA cleavage activity.

Metnase (SETMAR) is a SET and transposase fusion protein that promotes in vivo end joining activity and mediates genomic integration of foreign DNA. Recent studies showed that Metnase retained most of the transposase activities, including 5'-terminal inverted repeat (TIR)-specific binding and assembly of a paired end complex, and cleavage of the 5'-end of the TIR element. Here we show that R432 within the helix-turn-helix motif is critical for sequence-specific recognition, as the R432A mutation abolishes its TIR-specific DNA binding activity.

The sesquiterpene lactone parthenolide in combination with docetaxel reduces metastasis and improves survival in a xenograft model of breast cancer.

Parthenolide, a sesquiterpene lactone, shows antitumor activity in vitro, which correlates with its ability to inhibit the DNA binding of the antiapoptotic transcription factor nuclear factor kappaB (NF-kappaB) and activation of the c-Jun NH(2)-terminal kinase. In this study, we investigated the chemosensitizing activity of parthenolide in vitro as well as in MDA-MB-231 cell-derived xenograft metastasis model of breast cancer. HBL-100 and MDA-MB-231 cells were used to measure the antitumor and chemosensitizing activity of parthenolide in vitro.