A novel nuclear receptor ERRgamma3. Although ERRgamma3 itself lacks a DNA-binding domain, it has an effect of potentiating the transcriptional activation effect of an arbitrary nuclear receptor such as ERR, ER or TR. Moreover, it is found out that known proteins ERRgamma1 and ERRgamma2 have an effect of potentiating the transcriptional activation of other nuclear receptors similar to ERRgamma3. Thus, a method of evaluating the function of these ERRgamma subtypes of controlling the transcriptional activation effect of other nuclear receptors and a screening method based on this evaluation method are provided.
