Potential coactivator of the androgen receptor. Mediates STAT3 degradation. May play critical roles in two RAB6-dependent retrograde transport processes: one from endosomes to the Golgi and the other from the Golgi to the ER. This protein binds the HIV-1 TATA element and inhibits transcriptional activation by the TATA-binding protein (TBP). Interacts with TRNP1; may regulate TRNP1 proteasomal degradation (By similarity). Component of the SNF/SWI transcription factor complexes. Interacts with RAB6A. Interacts with STAT3 and FER. Interacts with TCEB1. Concentrated at the budding structures localized at the tips of cisternae. Down-regulated in malignant brain tumors. The Elongin BC complex binding domain is also known as BC-box with the consensus [APST]-L-x(3)-C-x(3)-[AILV]. Phosphorylated by FER.