Steroids cross the cell membrane by diffusion and bind to a steroid-specific cytoplasmic receptor. The receptor-steroid complex then translocates to the nucleus and acts to up- or down-regulate expression of certain genes by increasing or decreasing the transcription of their mRNAs. Sometimes this action is linked to interaction of the complex with transcription activator protein, an enhancer of gene transcription. | Steroids cross the cell membrane by diffusion and bind to a steroid-specific cytoplasmic receptor. The receptor-steroid complex then translocates to the nucleus and acts to up- or down-regulate expression of certain genes by increasing or decreasing the transcription of their mRNAs. Sometimes this action is linked to interaction of the complex with transcription activator protein, an enhancer of gene transcription. |