Proteomic profiling of lipid droplet proteins in hepatoma cell lines expressing hepatitis C virus core protein.
Hepatitis C virus (HCV) core protein has been suggested to play crucial roles in the pathogeneses of liver steatosis and hepatocellular carcinomas due to HCV infection. Intracellular HCV core protein is localized mainly in lipid droplets, in which the core protein should exert its significant biological/pathological functions. In this study, we performed comparative proteomic analysis of lipid droplet proteins in core-expressing and non-expressing hepatoma cell lines. We identified 38 proteins in the lipid droplet fraction of core-expressing (Hep39) cells and 30 proteins in that of non-expressing (Hepswx) cells by 1-D-SDS-PAGE/MALDI-TOF mass spectrometry (MS) or direct nanoflow liquid chromatography-MS/MS. Interestingly, the lipid droplet fraction of Hep39 cells had an apparently lower content of adipose differentiation-related protein and a much higher content of TIP47 than that of Hepswx cells, suggesting the participation of the core protein in lipid droplet biogenesis in HCV-infected cells. Another distinct feature is that proteins involved in RNA metabolism, particularly DEAD box protein 1 and DEAD box protein 3, were detected in the lipid droplet fraction of Hep39 cells. These results suggest that lipid droplets containing HCV core protein may participate in the RNA metabolism of the host and/or HCV, affecting the pathopoiesis and/or virus replication/production in HCV-infected cells.
Sato
Shigeko
S
Department of Biochemistry and Cell Biology and Department of Virology II, National Institute of Infectious Diseases, Tokyo 162-8640.
Fukasawa
Masayoshi
M
Yamakawa
Yoshio
Y
Natsume
Tohru
T
Suzuki
Tetsuro
T
Shoji
Ikuo
I
Aizaki
Hideki
H
Miyamura
Tatsuo
T
Nishijima
Masahiro
M
D002460:Cell Line; D053487:DEAD-box RNA Helicases; D016174:Hepacivirus / Q000472:pathogenicity / Q000502:physiology*; D018936:Hepatitis C Antigens / Q000235:genetics* / Q000302:isolation & purification*; D006801:Humans; D050356:Lipid Metabolism; D008099:Liver / Q000821:virology; D040901:Proteomics / Q000379:methods; D020365:RNA Helicases / Q000378:metabolism; D014758:Viral Core Proteins / Q000235:genetics* / Q000302:isolation & purification*; D014779:Virus Replication
D018936:Hepatitis C Antigens; D014758:Viral Core Proteins; C499352:core protein p22, Hepatitis C virus; C069130:nucleocapsid protein, Hepatitis C virus; C119332:DDX3X protein, human; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases