In vitro kinase assays Biotinylated GST Gag proteins were synthesized in wheat germ cell free e tracts as described above. The synthe sized GST Gag proteins were then purified using strep tavidin conjugated magnet beads. The purified proteins on the beads were then incubated with recombi nant aPKCiota in a 50 ul reac tion mi ture containing 20 mM Tris HCl pH 7. 5, 1 mM EDTA, 1 mM dithiothreitol, 150 mM NaCl, 5 mM MgCl2, 0. 05% Tween 20, 100 uM ATP and 2 uCi ATP. The reaction mi ture was then incubated for 1 h at 37 C, and the products were subjected to electrophoresis on 10% SDS polyacrylamide gels and were detected with an image guider. Western blotting Cells were harvested at the indicated post treatment time points with do ycycline, washed with phosphate buffer saline, and treated with lysis buffer for 20 min on ice.

Multiple protease inhibitors, 200 uM sodium vanadate and 20 mM sodium fluoride were then added to the buffer. The samples were cen trifuged at 18,000 g for 10 min at 4 C, and clarified cell e tracts were assayed for protein concentration using a Bio Rad kit. Equal amounts of proteins were resolved by SDS 10% polyacrylamide gel electrophoresis in running buffer. The separated proteins were transferred to polyvinylidene difluoride membrane. The membranes were washed with blotting buffer and blocked in 10% low fat powdered milk in blotting buffer for 1 h at room temperature. Primary antibodies were added at appropriate dilutions in 3% bovine serum albu min in blotting buffer and rocked overnight at 4 C.

The membranes were then further washed in blotting buffer and incubated with a horseradish pero idase conjugated secondary antibody at room temperature for 1 h. Target proteins were detected with an enhanced chemilumine scence detection system. Images were processed using Fluor Chem FC2 with a cooled charge coupled device camera and assembled using Adobe Photoshop CS5 E tended. Identification of phosphorylation sites on HIV 1 gag by mass spectrometry Samples were separated by SDS PAGE and the gel was stained with Coomassie brilliant blue. Gag was e cised from the stained gel and digested with trypsin in 50 mM NH4HCO3 for 12 h at 37 C. Phospho peptides were enriched using Titansphere Phos TiO Kit, in accordance with the manufacturers instructions. The enriched phosphopep tides were then analyzed by MALDI TOF TOF MS.

The Dacomitinib resulting raw MS spectrum was processed using the 4000 Series E plorer Software to generate Mascot generic format. The obtained MS and MS MS data were then searched against the SwissProt database using Mascot version 2. 4. 1 software, to identify proteins and protein modification. The search parameters were as follows trypsin digestion with two missed cleavages permitted, variable modifications, peptide mass tolerance for MS data 0. 15 Da, and frag ment mass tolerance 0. 3 Da.