Bovine HEXIM1 inhibits bovine immunodeficiency virus replication through regulating BTat-mediated transactivation
- Equal contributors
1 Key Laboratory of Molecular Microbiology and Biotechnology (Ministry of Education) and Key Laboratory Microbial Functional Genomics (Tianjin), College of Life Sciences, Nankai University, Tianjin, 300071, China
2 College of Pharmacy and Tianjian Key Laboratory of Molecular Drug Research, Nankai University, Tianjin, 300071, China
Veterinary Research 2013, 44:21 doi:10.1186/1297-9716-44-21Published: 27 March 2013
The bovine immunodeficiency virus (BIV) transactivator (BTat) recruits the bovine cyclin T1 (B-cyclin T1) to the LTR to facilitate the transcription of BIV. Here, we demonstrate that bovine hexamethylene bisacetamide (HMBA)-induced protein 1 (BHEXIM1) inhibits BTat-mediated BIV LTR transcription. The results of in vivo and in vitro assays show direct binding of BHEXIM1 to the B-cyclin T1. These results suggest that the repression arises from BHEXIM1-BTat competition for B-cyclin T1, which allows BHEXIM1 to displace BTat from B-cyclin T1. Furthermore, we found that the C-terminal region and the centrally located region of BHEXIM1 are required for BHEXIM1 to associate with B-cyclin T1. Knockdown of BHEXIM1 enhances BIV replication. Taken together, our study provides the first clear evidence that BHEXIM1 is involved in BIV replication through regulating BTat-mediated transactivation.