Previous Article | Next Article ![]()
Journal of Virology, August 2000, p. 7391-7399, Vol. 74, No. 16
Graduate Institute of
Microbiology1 and Department of
Otolaryngology, National Taiwan University
Hospital,2 College of Medicine, National
Taiwan University, Taipei, Taiwan, Republic of China
Received 27 January 2000/Accepted 22 May 2000
The Zta protein is a key transactivator involved in initiating the
Epstein-Barr virus (EBV) lytic cascade. In addition to transactivating
many viral genes, Zta has the capacity to influence host cellular
signals by binding to promoter regions or by interacting with several
important cellular factors. Based on the observation that tyrosine
kinases play central roles in determining the fate of cells, a kinase
display assay was used to investigate whether cells expressing Zta
have an altered pattern of kinase expression. The assay revealed
that TRK-related tyrosine kinase (TKT) is expressed at
significant levels in Zta transfectants but not in control cells.
Additional evidence was obtained from Northern and Western blotting.
Importantly, the upregulation of phosphorylated TKT and TKT
downstream effector matrix metalloproteinase 1 in Zta transfectants
hinted that TKT might initiate a signaling cascade in Zta-expressing
cells. In addition, deletion analysis of the Zta protein revealed that
the transactivation and dimerization domains were both essential for
the upregulation of TKT transcription. Moreover, correlation of
expression levels of Zta and TKT transcripts in nasopharyngeal
carcinoma biopsy specimens was clearly demonstrated by quantitative PCR
(Q-PCR), which provides the first evidence for an effect of Zta on
cellular gene expression in vivo. These findings offer insight into the
virus-cell interactions and may help us elucidate the role of EBV in tumorigenesis.
0022-538X/00/$04.00+0
Copyright © 2000, American Society for Microbiology. All rights reserved.
Upregulation of Tyrosine Kinase TKT by the
Epstein-Barr Virus Transactivator Zta
*
Corresponding author. Mailing address: Graduate
Institute of Microbiology, College of Medicine, National Taiwan
University, Room 714, Number 1, Section 1, Jen-Ai Road, Taipei, Taiwan,
Republic of China. Phone: 886-2-2312-3456, ext. 8298. Fax:
886-2-2391-5180. E-mail:
chtsai{at}ha.mc.ntu.edu.tw.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»