Figure 2. Tetracycline-regulated ectopic expression of Flag-Krs1 protein in tetR-expressed 10T1/2-TR and T-REx293 cells. (A) Cultures of 10T1/2-TR-Flag-Krs1 (lane 1) were treated with 100 ng/ml tetracycline for 48 hrs (lane 2). (B) Cultures of T-REx293-Flag-Krs1 cells (lane 1) were treated with 100 ng/ml tetracycline for 48 hrs (lane 2). Thirty μg of cellular proteins in lysates were analyzed by Western immunoblotting using specific antibodies to Flag. Arrows indicate ectopically expressed Flag-Krs1 protein.