Activation of early gene transcription in polyomavirus BK by human immunodeficiency virus type 1 Tat Gorrill, Timothy and Feliciano, Mariha and Mukerjee, Ruma and Sawaya, Bassel E. and Khalili, Kamel and White, Martyn K.,, 87, 1557-1566 (2006), doi = https://doi.org/10.1099/vir.0.81569-0, publicationName = Microbiology Society, issn = 0022-1317, abstract= Polyomavirus BK (BKV) is a serious problem for immunocompromised patients, where latent virus can enter into the lytic cycle causing cytolytic destruction of host cells. BKV infects >80 % of the population worldwide during childhood and then remains in a latent state in the kidney. In the context of immunosuppression in kidney transplant patients, reactivation of the viral early promoter (BKVE) results in production of T antigen, enabling virus replication and transition from latency to the lytic phase, causing polyomavirus-associated nephropathy. Reactivation of BKV can also cause complications such as nephritis, atypical retinitis and haemorrhagic cystitis in AIDS patients. Here, the effects of human immunodeficiency virus type 1 (HIV-1) proteins Tat and Vpr on BKV transcription were investigated and it was demonstrated that Tat dramatically stimulated BKVE. Site-directed mutagenesis analysis of potential Tat-responsive transcriptional motifs complemented by an electrophoretic mobility shift assay (EMSA) showed that Tat activated BKVE by inducing binding of the NF-κB p65 subunit to a κB motif near the 3′ end of BKVE. In addition, a sequence within the 5′ UTR of BKVE transcripts (BKVE-TAR) was identified that is identical to the HIV-1 transactivation response (TAR) element. The BKVE-TAR sequence bound TAT in RNA EMSA assays and deletion of the BKVE-TAR sequence eliminated Tat transactivation of BKVE transcription. Thus, Tat positively affected BKVE transcription by a dual mechanism and this may be important in diseases involving BKV reactivation in AIDS patients., language=, type=