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The HBZ-SP1 Isoform of Human T-cell Leukemia Virus Type I Represses JunB Activity by Sequestration into Nuclear Bodies

Overview
Journal Retrovirology
Publisher Biomed Central
Specialty Microbiology
Date 2007 Feb 20
PMID 17306025
Citations 44
Authors
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Abstract

Background: The human T-cell leukemia virus type I (HTLV-I) basic leucine-zipper factor (HBZ) has previously been shown to modulate transcriptional activity of Jun family members. The presence of a novel isoform of HBZ, termed HBZ-SP1, has recently been characterized in adult T-cell leukemia (ATL) cells and has been found to be associated with intense nuclear spots. In this study, we investigated the role of these nuclear bodies in the regulation of the transcriptional activity of JunB.

Results: Using fluorescence microscopy, we found that the HBZ-SP1 protein localizes to intense dots corresponding to HBZ-NBs and to nucleoli. We analyzed the relative mobility of the EGFP-HBZ-SP1 fusion protein using fluorescence recovery after photobleaching (FRAP) analysis and found that the deletion of the ZIP domain perturbs the association of the HBZ-SP1 protein to the HBZ-NBs. These data suggested that HBZ needs cellular partners, including bZIP factors, to form HBZ-NBs. Indeed, by cotransfection experiments in COS cells, we have found that the bZIP factor JunB is able to target delocalized form of HBZ (deleted in its nuclear localization subdomains) into the HBZ-NBs. We also show that the viral protein is able to entail a redistribution of JunB into the HBZ-NBs. Moreover, by transfecting HeLa cells (known to express high level of JunB) with a vector expressing HBZ-SP1, the sequestration of JunB to the HBZ-NBs inhibited its transcriptional activity. Lastly, we analyzed the nuclear distribution of HBZ-SP1 in the presence of JunD, a Jun family member known to be activated by HBZ. In this case, no NBs were detected and the HBZ-SP1 protein was diffusely distributed throughout the nucleoplasm.

Conclusion: Our results suggest that HBZ-mediated sequestration of JunB to the HBZ-NBs may be causing the repression of JunB activity in vivo.

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References
1.
Aronheim A, Zandi E, Hennemann H, Elledge S, Karin M . Isolation of an AP-1 repressor by a novel method for detecting protein-protein interactions. Mol Cell Biol. 1997; 17(6):3094-102. PMC: 232162. DOI: 10.1128/MCB.17.6.3094. View

2.
Curtiss V, Smilde R, McGuire K . Requirements for interleukin 2 promoter transactivation by the Tax protein of human T-cell leukemia virus type 1. Mol Cell Biol. 1996; 16(7):3567-75. PMC: 231352. DOI: 10.1128/MCB.16.7.3567. View

3.
Matsumoto J, Ohshima T, Isono O, Shimotohno K . HTLV-1 HBZ suppresses AP-1 activity by impairing both the DNA-binding ability and the stability of c-Jun protein. Oncogene. 2004; 24(6):1001-10. DOI: 10.1038/sj.onc.1208297. View

4.
Hivin P, Frederic M, Arpin-Andre C, Basbous J, Gay B, Thebault S . Nuclear localization of HTLV-I bZIP factor (HBZ) is mediated by three distinct motifs. J Cell Sci. 2005; 118(Pt 7):1355-62. DOI: 10.1242/jcs.01727. View

5.
Gallo R . The discovery of the first human retrovirus: HTLV-1 and HTLV-2. Retrovirology. 2005; 2:17. PMC: 555587. DOI: 10.1186/1742-4690-2-17. View