Transfection of P311 into C310 T1/2 cells stimulates muscle-specific transcription factors and induces SM α-actin synthesis. (a) RT-PCR showing mRNA for P311 and muscle-specific transcription factors in cells transfected with empty vector or transfected with P311. P311-expressing cells have higher levels of muscle-specific transcription factors than their control counterparts, with the exception of Myf5, which is downregulated. (b) Immunoblots showing increase in the synthesis of muscle-related transcription factors in P311-transfected cells compared with controls. The membrane used for detection of MyoD was stained with Coomassie blue to show equal protein loading. (c) Immunoblots demonstrating P311-induced upregulation of SM α-actin but absence of other SM and STM markers. (d) RT-PCR showing presence of mRNA for desmin and SM-myosin in control and P311-expressing cells, with some increment in SM-myosin message, which was consistent among experiments.