TY - JOUR
T1 - The hepatitis B virus-encoded transcriptional trans-activator hbx appears to be a novel protein serine/threonine kinase
AU - Wu, Jane Y.
AU - Zhou, Zhuo Yuan
AU - Judd, Amrit
AU - Cartwright, Christine A.
AU - Robinson, William S.
N1 - Funding Information:
We thank Yi Rao for helpful discussion and advice, Drs. Ethan Bier and Edward Giniger for helpful comments, Jeff Halaas for technical assistance, Dr. A. Moriarty for kindly providing antibodies, and Drs. Rosenberg and Studier for providing the T7 expression system. This work was supported by NIH research grant All3528 and ACS CD-400 (to C. A. C.). The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked “advertisement” in accordance with 18 USC Section 1734 solely to indicate this fact.
PY - 1990/11/16
Y1 - 1990/11/16
N2 - To study the functional mechanism of the hepatitis B virus (HBV) X (hbx) gene product, we have expressed the hbx protein in E. coli and purified it by HPLC. The purified hbx protein was shown to be active in trans-activating transcription directed by the LTR sequence of HIV-1. The hbx protein was found to have an intrinsic serine/threonine protein kinase activity. The hbx protein was detected in hepatitis B virions, and tryptic phosphopeptide maps of the hbx protein phosphorylated in the virion and of the in vitro phosphorylated bacterially expressed hbx protein were similar. Inactivation of the hbx protein by heat, protein-denaturing agents, or an ATP affinity analog, p-fluorosulfonyl-benzoyl 5′-adenosine, resulted in loss of both protein kinase activity and trans-activation activity. These results suggest that the HBV-encoded trans-activator hbx is a novel protein kinase.
AB - To study the functional mechanism of the hepatitis B virus (HBV) X (hbx) gene product, we have expressed the hbx protein in E. coli and purified it by HPLC. The purified hbx protein was shown to be active in trans-activating transcription directed by the LTR sequence of HIV-1. The hbx protein was found to have an intrinsic serine/threonine protein kinase activity. The hbx protein was detected in hepatitis B virions, and tryptic phosphopeptide maps of the hbx protein phosphorylated in the virion and of the in vitro phosphorylated bacterially expressed hbx protein were similar. Inactivation of the hbx protein by heat, protein-denaturing agents, or an ATP affinity analog, p-fluorosulfonyl-benzoyl 5′-adenosine, resulted in loss of both protein kinase activity and trans-activation activity. These results suggest that the HBV-encoded trans-activator hbx is a novel protein kinase.
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U2 - 10.1016/0092-8674(90)90135-2
DO - 10.1016/0092-8674(90)90135-2
M3 - Article
C2 - 2225072
AN - SCOPUS:0025241104
SN - 0092-8674
VL - 63
SP - 687
EP - 695
JO - Cell
JF - Cell
IS - 4
ER -
