Previous Article | Next Article 
Journal of Virology, November 2000, p. 9953-9963, Vol. 74, No. 21
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Conserved Regions in the Epstein-Barr Virus Leader Protein Define
Distinct Domains Required for Nuclear Localization and Transcriptional
Cooperation with EBNA2
RongSheng
Peng,
Jie
Tan, and
Paul D.
Ling*
Division of Molecular Virology, Baylor
College of Medicine, Houston, Texas 77030
Received 5 May 2000/Accepted 10 August 2000
Epstein-Barr virus (EBV) EBNA-LP is a latent protein whose function
is not fully understood. Recent studies have shown that EBNA-LP may be
an important EBNA2 cofactor by enhancing EBNA2 stimulation of the
latency C and LMP-1 promoters. To further our understanding of EBNA-LP
function, we have introduced a series of mutations into evolutionarily
conserved regions and tested the mutant proteins for the ability to
enhance EBNA2 stimulation of the latency C and LMP-1 promoters. Three
conserved regions (CR1 to CR3) are located in the repeat domains that
are essential for the EBNA2 cooperativity function. In addition, three
serine residues are also well conserved in the repeat domains.
Clustered alanine mutations were introduced into CR1 to CR3, and the
conserved serines were also changed to alanine residues in an EBNA-LP
with two repeats, which is the minimal protein able to cooperate with EBNA2. Mutations introduced into CR1a had no effect on EBNA-LP function, while mutations introduced into CR1b resulted in EBNA-LP with
slightly decreased activity. Mutations in CR1c and CR2 resulted in
proteins that no longer localized exclusively to the nucleus and also
had no EBNA2 cooperation activity. Mutations introduced into conserved
serines S5/71 resulted in proteins with slightly higher activity, while
mutations introduced into conserved serines S35/101 or in CR3 (which
contains S60/126) resulted in EBNA-LP proteins with substantially
reduced activity. The potential karyophilic signals within EBNA-LP CR1c
and CR2 were also examined by introducing oligonucleotides encoding
these positively charged amino acid groupings into a cytoplasmic test
protein, herpes simplex virus
IE175, and by examining the
intracellular localization of the resulting proteins. This assay
identified a strong nuclear localization signal between EBNA-LP amino
acids 43 and 50 (109 to 117 in the second W repeat) comprising CR2,
while EBNA-LP amino acids 29 to 36 (91 to 98 in the second W repeat)
were unable to function independently as a nuclear localization signal.
However, a combination of amino acids 29 to 50 resulted in more
efficient nuclear localization than with amino acids 43 to 50 alone.
These results indicate that EBNA-LP has a bipartite nuclear
localization signal and that efficient nuclear localization is
essential for EBNA2 cooperativity function. Interestingly, EBNA-LP with
only a single repeat localized exclusively to the cytoplasm, providing
an explanation for why this isoform has no activity. In addition, two
conserved serine residues which are distinct from nuclear import
functions are important for EBNA2 cooperativity function.
*
Corresponding author. Mailing address: Division of
Molecular Virology and Microbiology, Baylor College of Medicine, Mail
Stop BCM-385, One Baylor Plaza, Houston, TX 77030. Phone: (713)
798-8474. Fax: (713) 798-3586. E-mail:
pling{at}bcm.tmc.edu.
Journal of Virology, November 2000, p. 9953-9963, Vol. 74, No. 21
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
This article has been cited by other articles:
-
Ling, P. D., Tan, J., Peng, R.
(2009). Nuclear-Cytoplasmic Shuttling Is Not Required for the Epstein-Barr Virus EBNA-LP Transcriptional Coactivation Function. J. Virol.
83: 7109-7116
[Abstract]
[Full Text]
-
Tierney, R., Nagra, J., Hutchings, I., Shannon-Lowe, C., Altmann, M., Hammerschmidt, W., Rickinson, A., Bell, A.
(2007). Epstein-Barr Virus Exploits BSAP/Pax5 To Achieve the B-Cell Specificity of Its Growth-Transforming Program. J. Virol.
81: 10092-10100
[Abstract]
[Full Text]
-
Garibal, J., Hollville, E., Bell, A. I., Kelly, G. L., Renouf, B., Kawaguchi, Y., Rickinson, A. B., Wiels, J.
(2007). Truncated Form of the Epstein-Barr Virus Protein EBNA-LP Protects against Caspase-Dependent Apoptosis by Inhibiting Protein Phosphatase 2A. J. Virol.
81: 7598-7607
[Abstract]
[Full Text]
-
Peng, C.-W., Zhao, B., Chen, H.-C., Chou, M.-L., Lai, C.-Y., Lin, S.-Z., Hsu, H.-Y., Kieff, E.
(2007). Hsp72 up-regulates Epstein-Barr virus EBNALP coactivation with EBNA2. Blood
109: 5447-5454
[Abstract]
[Full Text]
-
Portal, D., Rosendorff, A., Kieff, E.
(2006). Epstein-Barr nuclear antigen leader protein coactivates transcription through interaction with histone deacetylase 4. Proc. Natl. Acad. Sci. USA
103: 19278-19283
[Abstract]
[Full Text]
-
Maruo, S., Johannsen, E., Illanes, D., Cooper, A., Zhao, B., Kieff, E.
(2005). Epstein-Barr Virus Nuclear Protein 3A Domains Essential for Growth of Lymphoblasts: Transcriptional Regulation through RBP-J{kappa}/CBF1 Is Critical. J. Virol.
79: 10171-10179
[Abstract]
[Full Text]
-
Peng, R., Moses, S. C., Tan, J., Kremmer, E., Ling, P. D.
(2005). The Epstein-Barr Virus EBNA-LP Protein Preferentially Coactivates EBNA2-Mediated Stimulation of Latent Membrane Proteins Expressed from the Viral Divergent Promoter. J. Virol.
79: 4492-4505
[Abstract]
[Full Text]
-
Gordadze, A. V., Onunwor, C. W., Peng, R., Poston, D., Kremmer, E., Ling, P. D.
(2004). EBNA2 Amino Acids 3 to 30 Are Required for Induction of LMP-1 and Immortalization Maintenance. J. Virol.
78: 3919-3929
[Abstract]
[Full Text]
-
Peng, C.-W., Xue, Y., Zhao, B., Johannsen, E., Kieff, E., Harada, S.
(2004). Direct interactions between Epstein-Barr virus leader protein LP and the EBNA2 acidic domain underlie coordinate transcriptional regulation. Proc. Natl. Acad. Sci. USA
101: 1033-1038
[Abstract]
[Full Text]
-
Kato, K., Yokoyama, A., Tohya, Y., Akashi, H., Nishiyama, Y., Kawaguchi, Y.
(2003). Identification of protein kinases responsible for phosphorylation of Epstein-Barr virus nuclear antigen leader protein at serine-35, which regulates its coactivator function. J. Gen. Virol.
84: 3381-3392
[Abstract]
[Full Text]
-
Maruo, S., Johannsen, E., Illanes, D., Cooper, A., Kieff, E.
(2003). Epstein-Barr Virus Nuclear Protein EBNA3A Is Critical for Maintaining Lymphoblastoid Cell Line Growth. J. Virol.
77: 10437-10447
[Abstract]
[Full Text]
-
Zhao, B., Dalbies-Tran, R., Jiang, H., Ruf, I. K., Sample, J. T., Wang, F., Sample, C. E.
(2003). Transcriptional Regulatory Properties of Epstein-Barr Virus Nuclear Antigen 3C Are Conserved in Simian Lymphocryptoviruses. J. Virol.
77: 5639-5648
[Abstract]
[Full Text]
-
Johansen, L. M., Deppmann, C. D., Erickson, K. D., Coffin, W. F. III, Thornton, T. M., Humphrey, S. E., Martin, J. M., Taparowsky, E. J.
(2003). EBNA2 and Activated Notch Induce Expression of BATF. J. Virol.
77: 6029-6040
[Abstract]
[Full Text]
-
Igarashi, M., Kawaguchi, Y., Hirai, K., Mizuno, F.
(2003). Physical interaction of Epstein-Barr virus (EBV) nuclear antigen leader protein (EBNA-LP) with human oestrogen-related receptor 1 (hERR1): hERR1 interacts with a conserved domain of EBNA-LP that is critical for EBV-induced B-cell immortalization. J. Gen. Virol.
84: 319-327
[Abstract]
[Full Text]
-
Han, I., Xue, Y., Harada, S., Orstavik, S., Skalhegg, B., Kieff, E.
(2002). Protein Kinase A Associates with HA95 and Affects Transcriptional Coactivation by Epstein-Barr Virus Nuclear Proteins. Mol. Cell. Biol.
22: 2136-2146
[Abstract]
[Full Text]
-
Tanaka, M., Yokoyama, A., Igarashi, M., Matsuda, G., Kato, K., Kanamori, M., Hirai, K., Kawaguchi, Y., Yamanashi, Y.
(2002). Conserved Region CR2 of Epstein-Barr Virus Nuclear Antigen Leader Protein Is a Multifunctional Domain That Mediates Self-Association as well as Nuclear Localization and Nuclear Matrix Association. J. Virol.
76: 1025-1032
[Abstract]
[Full Text]
-
Lin, J., Johannsen, E., Robertson, E., Kieff, E.
(2002). Epstein-Barr Virus Nuclear Antigen 3C Putative Repression Domain Mediates Coactivation of the LMP1 Promoter with EBNA-2. J. Virol.
76: 232-242
[Abstract]
[Full Text]
-
McCann, E. M., Kelly, G. L., Rickinson, A. B., Bell, A. I.
(2001). Genetic analysis of the Epstein-Barr virus-coded leader protein EBNA-LP as a co-activator of EBNA2 function. J. Gen. Virol.
82: 3067-3079
[Abstract]
[Full Text]
-
Dufva, M., Olsson, M., Rymo, L.
(2001). Epstein-Barr virus nuclear antigen 5 interacts with HAX-1, a possible component of the B-cell receptor signalling pathway. J. Gen. Virol.
82: 1581-1587
[Abstract]
[Full Text]
-
Gordadze, A. V., Peng, R., Tan, J., Liu, G., Sutton, R., Kempkes, B., Bornkamm, G. W., Ling, P. D.
(2001). Notch1IC Partially Replaces EBNA2 Function in B Cells Immortalized by Epstein-Barr Virus. J. Virol.
75: 5899-5912
[Abstract]
[Full Text]
-
Yokoyama, A., Tanaka, M., Matsuda, G., Kato, K., Kanamori, M., Kawasaki, H., Hirano, H., Kitabayashi, I., Ohki, M., Hirai, K., Kawaguchi, Y.
(2001). Identification of Major Phosphorylation Sites of Epstein-Barr Virus Nuclear Antigen Leader Protein (EBNA-LP): Ability of EBNA-LP To Induce Latent Membrane Protein 1 Cooperatively with EBNA-2 Is Regulated by Phosphorylation. J. Virol.
75: 5119-5128
[Abstract]
[Full Text]