FIG. 8.

Kinetics of host protein synthesis shutoff by the AAPA mutant. Cells were infected with either WT virus or the AAPA mutant (MUT) virus at an MOI of 10. At the times indicated, the cells were pulse-labeled for 15 min with [³⁵S]methionine and lysed in detergent buffer. A portion of the cell lysate was analyzed by SDS-PAGE followed by autoradiography. Labeled uninfected cells (MOCK) served as a control. (B) The amount of ³⁵S-labeled host proteins in each lane was determined by quantitating a representative area on the gel (indicated by the asterisk in panel A) with a STORM Phosphorimager and ImageQuant software (Molecular Dynamics). The amount of host proteins in the uninfected cells (control) was considered to be 100%. The extent of host shutoff was expressed as a percentage of the amount of host proteins in the control. The extent of host shutoff caused by the AAPA mutant at an MOI of 50 is shown in the inset (C).