TY - JOUR
T1 - The interaction of hepatitis B virus X protein and protein phosphatase type 2 Cα and its effect on IL-6
AU - Kim, Ji Su
AU - Rho, Bo young
AU - Lee, Tae Ho
AU - Lee, Jae Myun
AU - Kim, Se Jong
AU - Park, Jeon Han
PY - 2006/12/8
Y1 - 2006/12/8
N2 - HBx has been suggested as an important determinant mediating the pathological effects of HBV via interacting with various cellular proteins. To identify new HBx-interacting proteins and elucidate a possible mechanism associated with HBx and HBx-interacting proteins in hepatocellular carcinoma, yeast two-hybrid screening was performed. We identified a novel HBx-interacting protein, serine/threonine protein phosphatase PP2Cα, and investigated the effects of PP2Cα on HBx-mediated IL-6 regulation. The interaction between endogenous PP2Cα, and HBx was confirmed by co-immunoprecipitation. Recombinant HBx dose-dependently reduced enzyme activity of recombinant PP2Cα in vitro. While ectopically expressed PP2Cα in Cos-7 and Huh-7 cells reduced the expression of IL-6, overexpressed HBx with recombinant HBx-expressing adenovirus overcame PP2Cα-mediated IL-6 downregulation. In the response of IL-6, HBx phosphorylated STAT3 and recovered PP2Cα-mediated dephosphorylation of STAT3. These results supported that HBx might play a crucial role in HBV-associated hepatocarcinogenesis even in cases where cells express a negative regulator, PP2Cα.
AB - HBx has been suggested as an important determinant mediating the pathological effects of HBV via interacting with various cellular proteins. To identify new HBx-interacting proteins and elucidate a possible mechanism associated with HBx and HBx-interacting proteins in hepatocellular carcinoma, yeast two-hybrid screening was performed. We identified a novel HBx-interacting protein, serine/threonine protein phosphatase PP2Cα, and investigated the effects of PP2Cα on HBx-mediated IL-6 regulation. The interaction between endogenous PP2Cα, and HBx was confirmed by co-immunoprecipitation. Recombinant HBx dose-dependently reduced enzyme activity of recombinant PP2Cα in vitro. While ectopically expressed PP2Cα in Cos-7 and Huh-7 cells reduced the expression of IL-6, overexpressed HBx with recombinant HBx-expressing adenovirus overcame PP2Cα-mediated IL-6 downregulation. In the response of IL-6, HBx phosphorylated STAT3 and recovered PP2Cα-mediated dephosphorylation of STAT3. These results supported that HBx might play a crucial role in HBV-associated hepatocarcinogenesis even in cases where cells express a negative regulator, PP2Cα.
UR - http://www.scopus.com/inward/record.url?scp=33750316808&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33750316808&partnerID=8YFLogxK
U2 - 10.1016/j.bbrc.2006.10.028
DO - 10.1016/j.bbrc.2006.10.028
M3 - Article
C2 - 17055456
AN - SCOPUS:33750316808
SN - 0006-291X
VL - 351
SP - 253
EP - 258
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -
