ACTIVATION OF BLV TRANSCRIPTION BY NF-KAPPA-B AND TAX

Bovine leukemia virus (BLV) is the causative agent of bovine leukosis, a naturally occurring fatal disease in cattle. BLV transcription is r egulated by cellular transcription factors and the virally encoded onc oprotein Tax. In this report, we investigated the functional role of t he putative NF-kappa B binding site recently identified in the BLV pro moter; Our studies indicate that the kappa B binding motif acts as a f unctional enhancer in the presence of the cellular NF-kappa B proteins . Furthermore, the kappa B site together with a single 21-bp repeat co nfers strong activation of BLV transcription in the presence the NF-ka ppa B proteins and lax. These results suggest that cellular NF-kappa B may he involved in the regulation of BLV transcription and activation of the virus from latency, (C) 1998 Academic Press.