[Synergetic transactivating functions of HCV core and truncated HBV middle surface protein].
OBJECTIVE
To investigate the synergetic transactivating functions of HCV core and truncated HBV middle surface proteins.


METHODS
Two recombinant expression plasmids harboring HCV core and C-terminally truncated HBV middle surface protein gene were constructed, respectively. The plasmids were transfected into HepG2 cells and cotransfected HepG2 cells with reporter plasmid pSV-lacZ by lipofectamine plus reagents. The transient expressed viral proteins were identified at the transcription and translation levels. The activity of beta-galactosidase was detected, which reflected the transactivating function of the proteins.


RESULTS
The protein expression of plasmids was detected in soluble cell extracts of transiently transfected HepG2 cells. HCV core protein activated the beta-galactosidase expression at a value of 4.6 times higher than the control, while C-terminally truncated HBV middle surface protein activated at a value of 3.2 times. It reached 8.4 times transfected with the plasmids simultaneously. The transactivating effect was dose dependent.


CONCLUSIONS
It is suggested that the two kinds of virus proteins have transactivating effect on SV40 early promoter/enhancer, and they act synergistically. These contribute to explain the mechanisms of liver injury or tumorigenesis induced by HCV or/and HBV infection.
Liu
Yan
Y
Gene Therapy Research Center, Institute of Infectious Diseases, 302nd Hospital of PLA, Beijing 100039, China.
Cheng
Jun
J
Wang
Gang
G
Li
Ke
K
Duan
Huijuan
H
Wang
Lin
L
Li
Li
L
Zhang
Ling Xia
LX
Chen
Jumei
J
D056945:Hep G2 Cells; D006509:Hepatitis B / Q000235:genetics / Q000378:metabolism*; D006526:Hepatitis C / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D010957:Plasmids; D011401:Promoter Regions, Genetic; D015533:Transcriptional Activation; D014162:Transfection; D014758:Viral Core Proteins / Q000235:genetics / Q000378:metabolism*; D001616:beta-Galactosidase
D008565:Membrane Proteins; D014758:Viral Core Proteins; D001616:beta-Galactosidase