Figure 3
From: Hepatic STAMP2 decreases hepatitis B virus X protein-associated metabolic deregulation
STAMP2 prevents degradation of IRS1 by HBx. (A) HepG2 and HepG2-HBx cells were transfected with empty vector or GFP/STAMP2 expression plasmid, followed by treatment with insulin at concentrations from 0 to 200 nM for 1 h. Whole cell lysates were subjected to immunoblotting for IRS1 and IRα (left), followed by image analysis of IRS1 and IRα protein expression by densitometry (right). Western blotting bands were quantified using ImageJ version 1.35d (National Institutes of Health Image software). (B, C) HepG2 cells were transiently transfected with mammalian HBx and/or GFP/STAMP2 expression vectors. Whole cell lysates were subjected to immunoblotting for IRS1 and STAMP2. Total RNA was prepared from cells, after which mRNA levels of IRS1, STAMP2, and β-actin were assessed by RT-PCR. (D) HepG2 cells were transiently transfected with mammalian HBx and/or GFP/STAMP2 expression vectors. Whole cell lysates were subjected to Western blotting with anti-IRS1, anti-STAMP2, and anti-actin antibodies. (E) HepG2 cells were transiently transfected with mammalian HBx, HA/ub, and/or GFP/STAMP2 expression vectors. Whole cell lysates were immunoprecipitated with anti-IRS1 antibody, followed by immunoblotting with anti-HA antibody.
