9.B.208.1.3
Nuclear receptor subfamily 1 group I member 2, or the pregnane X recpetor, of 434 aas and 0 TMSs.  It binds and is activated by a variety of endogenous and xenobiotic compounds and is a transcription factor that activates the transcription of multiple genes involved in the metabolism and secretion of potentially harmful xenobiotics, drugs and endogenous compounds. It is activated by the antibiotic rifampicin and various plant metabolites, such as hyperforin, guggulipid, colupulone, and isoflavones in a species-specific fashion. It is also activated by naturally occurring steroids, such as pregnenolone and progesterone (Lehmann et al. 1998; Geick et al. 2001; Watkins et al. 2003; Li et al. 2009).