CVB3 infection induces SG formation at ∼3 hrs and disassembly at ∼5 hrs post-infection.

<p>(A, B) Representative confocal images of intracellular localization of G3BP1, TIA1 and HuR following CVB3 infection of HeLa cells. HeLa cells were transiently co-transfected with pEGFP-G3BP1 and either pDsRed-TIA1 (A) or pDsRed-HuR (B) for 48 hrs, followed by sham- or CVB3 infection at an MOI of 10 for various time points as indicated. Arsenite treatment at a dose of 50 mM for 1 hr was used as positive controls for inducing SG formation. Cell nuclei were counterstained with 4′, 6-diamidino-2-phenylindole (DAPI). (C) Representative confocal images of co-localization of poly-A-mRNA with G3BP1 during CVB3 infection. HeLa cells were transiently transfected with pEGFP-G3BP1 for 48 hrs, followed by sham- or CVB3 infection at an MOI of 10 for different time points as indicated. Poly-A-mRNA was detected by <i>in situ</i> hybridization using an oligo-dT probe synthetically conjugated to Cy3, followed by immunostaining for G3BP1. Cell nuclei were counterstained with DAPI. (D) Quantitation of G3BP1-SG formation from (A, B). Percent of cells expressing SGs was quantified as described in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0079546#s2" target="_blank">Materials and Methods</a> (mean ± SD, n = 10 images), #p<0.001. (E) Quantitation of poly-A granules from (C). Percent of cells expressing poly-A punctates was quantified as above. N.D., No statistical difference, *p<0.01. (F, G) Representative transmission (F) and immune-electron (G) microscope images. HeLa cells were either sham- or CVB3-infected at an MOI of 10 for 4 hrs. N and M indicate the nucleus and mitochondria, respectively. Arrow heads in (F) indicate ribosomal-like structures. Arrows in (G) indicate cytoplasmic aggregates that were stained positive for endogenous G3BP1.