FIG. 1.

PKR is transiently activated after HIV infection and is inhibited during active HIV replication. (A) HIV-1 pNL4-3 and pMAL infection kinetics. Jurkat cells were mock infected (dotted line) or were infected with HIV pNL4-3 (black line). Jurkat-CCR5 cells were infected with HIV-1 pMAL (gray line). Aliquots of cell supernatants were collected at different times and assayed for RT activity. (B) Protein expression of pNL4-3-infected Jurkat cells. For the upper four blots, 250 μg of whole-cell extracts from pNL4-3-infected Jurkat cells were subjected to SDS-10% PAGE and blotted with anti-P-PKR, anti-PKR, anti-HIV-p24, and anti-actin antibodies as indicated. For the middle two blots, 250-μg aliquots of the same extracts were subjected to a similar SDS-PAGE and blotted with anti-TRBPjbx and anti-actin antibodies as indicated. For the lower three blots, 250-μg aliquots of the same extracts were subjected to SDS-7.5% PAGE and blotted with anti-ADAR1 and anti-actin antibodies as indicated. The exposure was 10 times longer for ADAR1-p150 than for ADAR1-p110 and ADAR1-p150 where indicated. D-4, day 4. (C) Protein expression of mock-infected Jurkat cells. Aliquots (250 μg) of whole-cell extracts from mock-infected Jurkat cells were subjected to SDS-10% PAGE and blotted as described for panel B with the indicated antibodies. (D) Protein expression of pMAL-infected Jurkat-CCR5 cells. Aliquots (250 μg) of whole-cell extracts from pMAL-infected Jurkat-CCR5 cells were subjected to SDS-10% PAGE and SDS-7.5% PAGE and blotted as described for panel B with the indicated antibodies. (E) Ratio of P-PKR/PKR during HIV infection. The band intensity was digitized using Adobe Photoshop software from the bands shown in panel B for pNL4-3 and in panel D for pMAL. The P-PKR/PKR ratio was calculated by dividing the P-PKR intensity by the total PKR intensity of each band.