Abstract:

Abstract:Objective To explore the mechanism underlying Prohibitin 2 (PHB2)-mediated repression on myocyte enhancer factor 2 (MEF2) and facilitate the study of the role of PHB2 in other MEF2 positive cells. Methods Using lipofectamin transfection method, Hela cells were co-transfected with plasmid expressing PHB2 and MEF2 and luciferase reporter plasmid. 36 h after transfection, the recombinant proteins were tested with Western blotting and the activity of luciferase was measured with luminator in the supernatant of cell lysis.  Results Compared with the cells without PHB2 transfection, the inhibitory fold of co-transfected PHB2 on MEF2-dependent expression of luciferase was 0.28(P<0.01) and proportional to the amount of PHB2 expression. The activation fold of MEF2 transactivation domain on the expression of luciferase was 2.24±0.21 when co-transfected with PHB2, while it was 9.53±1.06 without PHB2 (P<0.01). Upon the treatment of TSA, the inhibitor for histone deacetylase (HDAC), the inhibitory fold of co-transfected PHB2 on MEF2 was changed from 0.38 to 0.98(P<0.01). Conclusion PHB2 represses the transcriptional activity of MEF2 by specifically acting on its transctivation domain and through HDAC to mediate the repression, but independently on MyoD and DNA binding activity of MEF2.

Key words: Prohibitin 2；myocyte enhancer factor 2；transcriptional repression；histone deacetylase