Transcriptional targets for pituitary tumor-transforming gene-1.

Pituitary tumor-transforming gene-1 (PTTG1) is a transforming gene first discovered in rat pituitary tumor cells. It possesses transcriptional activity and also has securin functions. Chromatin immunoprecipitation-on-chip study reveals that PTTG1 is a global transcription factor, which exerts its transcriptional activity either by directly binding to DNA or by interacting with proteins including PTTG1 binding factor, p53, Sp1, and upstream stimulatory factor 1. PTTG1 has several validated transcriptional targets that are involved in different cellular processes. PTTG1 activates c-Myc in NIH 3T3 cells, suggesting a role in cell transformation. PTTG1 induces fibroblast growth factor 2 expression and promotes tumor angiogenesis.It binds to and inhibits p53 transcriptional activity. PTTG1 activates cyclin D3 and represses p21 expression, indicating a role in cell cycle regulation and cell senescence. Here, we review PTTG1 transcriptional targets and their functions.