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Epstein‐Barr Virus (EBV) Nuclear Antigen Leader Protein (EBNA‐LP) Forms Complexes with a Cellular Anti‐Apoptosis Protein Bcl‐2 or Its EBV Counterpart BHRF1 through HS1‐Associated Protein X‐1
Author(s) -
Matsuda Go,
Nakajima Kaori,
Kawaguchi Yasushi,
Yamanashi Yuji,
Hirai Kanji
Publication year - 2003
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.2003.tb02790.x
Subject(s) - biology , fusion protein , apoptosis , microbiology and biotechnology , epstein–barr virus , virus , nuclear protein , antigen , viral protein , virology , gene , biochemistry , genetics , recombinant dna , transcription factor
Epstein‐Barr virus (EBV) nuclear antigen leader protein (EBNA‐LP) plays a critical role in EBV‐induced transformation. An earlier report (Y. Kawaguchi et al., J. Virol. 74: 10104–10111, 2000) showed that EBNA‐LP interacts with a cellular protein HS1‐associated protein X‐1 (HAX‐1). The predicted amino acid sequence of HAX‐1 exhibits similarity to that of another cellular protein Nip3 which has been shown to interact with cellular and viral anti‐apoptotic proteins such as Bcl‐2 and BHRF1, an EBV homolog of Bcl‐2. Here we investigated whether HAX‐1, like Nip3, interacts with Bcl‐2 proteins and report the following. (i) A purified chimeric protein consisting of gluthathione S‐transferase (GST) fused to BHRF1 (GST‐BHRF1) or Bcl‐2 (GST‐Bcl‐2) specifically pulled down HAX‐1 transiently expressed in COS‐7 cells. (ii) GST‐BHRF1 or GST‐Bcl‐2 was not able to pull down EBNA‐LP transiently expressed in COS‐7 cells, whereas each of the GST fusion proteins formed complexes with EBNA‐LP in the presence of HAX‐1. These results indicated that EBNA‐LP interacts with the viral and cellular Bcl‐2 proteins through HAX‐1, suggesting that EBNA‐LP possesses a potential function in the regulation of apoptosis in EBV‐infected cells.