Human parainfluenza virus type 1 regulates cholesterol biosynthesis and establishes quiescent infection in human airway cells
Fig 7
Ubiquitination and proteasomal degradation of HMGCR in hPIV1 infected cells.
(A) A549 cells were infected with hPIV1 or hPIV3 at an MOI of 5 for 2 days. Cells were then labeled with 35S-Met/Cys for 30 min and chased for either 2 or 4 h. HMGCR stability was analyzed by radio-immunoprecipitation. (B) A549 cells infected with hPIV1 at an MOI of 5 were treated with either MG132 (10 μM) and/or NH4Cl (20 mM) at 8 hpi for 8 h. Expression of HMGCR, SQLE, viral NP and β-actin were analyzed by immunoblotting. (C) A549 or HPBE cells were mock- or hPIV1-, hPIV3- infected at an MOI of 3 for 18 h. MG132 (10 μM) or DMSO was added and cells were cultured for an additional 8 h. HMGCR in cell lysates was immunoprecipitated using an HMGCR specific Ab and immunoblotting was performed to detect ubiquitin or HMGCR.