Fig 2.

 Heat shock factor activation in adult and aged rat white gastrocnemius muscles after heat shock. Protein extracts from white gastrocnemius muscles were incubated with a ³²P-labeled heat shock element (HSE) and analyzed by mobility shift–polyacrylamide gel electrophoresis as described in the text. Lane 1: free probe (FP); lane 2: unstressed (control) adult rat white gastocnemius muscle; lane 3: adult rat white gastocnemius muscle after a 10-minute, 40°C heat shock; lane 4: adult rat white gastocnemius muscle after a 10-minute, 41°C heat shock; lane 5: adult rat white gastocnemius muscle after a 10-minute, 42°C heat shock; lane 6: unstressed (control) aged rat white gastocnemius muscle; lane 7: aged rat white gastocnemius muscle after a 10-minute, 40°C heat shock; lane 8: aged rat white gastocnemius muscle after a 10-minute, 41°C heat shock; lane 9: aged rat white gastocnemius muscle after a 10-minute, 42°C heat shock; lane 10: protein extract from aged rat white gastocnemius muscle after a 10-minute, 42°C heat shock incubated with a 200-fold molar excess of unlabeled HSE. HSF, heat shock transcription factor complex; NSB, non–specific-binding