PCAF interacts with XBP-1S and mediates XBP-1S-dependent transcription

Lew, Qiao Jing; Chu, Kai Ling; Lee, Jialing; Koh, Poh Ling; Rajasegaran, Vikneswari; Teo, Jin Yuan; Chao, Sheng-Hao

PCAF is required for XBP-1S-mediated activation of HTLV-1 and BiP transcription Functional significance of the PCAF-XBP-1S interaction was assessed in the XBP-1S-dependent transcription assays. XBP-1S is known to regulate the transcription of HTLV-1 and cellular gene BiP (4, 26) . The luciferase reporters, in which the expression of luciferase was driven by HTLV-1 and BiP promoters (i.e. HTLV-Luc and BiP-Luc, respectively), were utilized in the study. In the XBP-1S co-transfected cells, more than 10-fold increases in luciferase expression were observed in HTLV-1 and BiP promoters ( Figure 3A and B). Further induction (more than 2-fold) of the XBP-1S-mediated activation of HTLV-1 and BiP promoters was detected in the PCAF-expressing cells ( Figure 3A and B) . However, overexpression of p300 had no significant effects on XBP-1S-dependent transcription ( Figure 3A and B) .