FIG. 2.

An IFN-β-elicited antiviral state in NB41A3 neuroblastomas does not interfere with the mono-ubiquitination of the VSV M protein. Neuroblastomas treated for 24 h with 400 U/mL IFN-β or vehicle alone were infected with VSV (MOI = 3), then metabolically labeled with ³⁵S-cysteine/methione (100 μCi/mL). At 6 hpi, cell lysates were harvested and immunoprecipitated with anti-VSV antiserum and anti-GAPDH polyclonal antibodies. Following denaturation in 30 μL PBS + 1% SDS at 100°C, and dilution in 300 μL RIP buffer (to dilute out SDS effects), another immunoprecipitation was performed on these samples, with anti-ubiquitin and anti-GAPDH polyclonal antibodies. Samples were then resolved via 14% SDS-PAGE, dehydrated, infiltrated with 2,5-diphenyloxazole, dried, and exposed to film. Densitometric analysis of GAPDH-normalized samples revealed no significant difference between the levels of anti-ubiquitin-recognized VSV M protein from mock- and IFN-β-treated NB41A3 cells. Figure representative of three replicate experiments.