FIG. 4.

Tat increases vGPCR-mediated phosphorylation of Akt and its downstream targets. GR3 cells were transfected with Tat101 DNA or a control vector, and cell lysates were analyzed by Western blotting as described in Materials and Methods. Blots were probed as follows: with antibodies against Tat or vGPCR (A), with antibodies against phosphorylated Akt or total Akt (B), with antibodies against phosphorylated GSK-3 or total GSK-3 (C), or with antibodies to phosphorylated FKHR, AFX, or BAD (D). Panel E shows the quantification of the blots performed with a PhosphorImager and measured in arbitrary pixel units. The solid bars show results from control cells, and the open bars show results from cells transfected with Tat101 DNA.