Multiprotein Bridging Factor-1 (MBF-1) Is a Cofactor for Nuclear Receptors that Regulate Lipid Metabolism

Carole Brendel, Laurent Gelman, Johan Auwerx
2002 Molecular Endocrinology  
Multiprotein bridging factor (MBF-1) is a cofactor that was first described for its capacity to modulate the activity of fushi tarazu factor 1, a nuclear receptor originally implicated in Drosophila development. Recently, it has been shown that human MBF-1 stimulates the transcriptional activity of steroidogenic factor 1, a human homolog of fushi tarazu factor 1, which is implicated in steroidogenesis. Here we show that this cofactor enhances the transcriptional activity of several nonsteroid
more » ... everal nonsteroid nuclear receptors that are implicated in lipid metabolism, i.e. the liver receptor homolog 1, the liver X receptor ␣, and PPAR␥. MBF-1 interacts with distinct domains in these receptors, depending on whether the receptor binds DNA as a monomer or as a heterodimer with RXR. MBF-1 does not possess any of the classical histone modifying activities such as histone acetyl-or methyl transferase activities, linked to chromatin remodeling, but interacts in vitro with the transcription factor IID complex. MBF-1 seems therefore to act as a bridging factor enabling interactions of nuclear receptors with the transcription machinery. (Molecular Endocrinology 16: 1367-1377, 2002) Abbreviations: Bm, Bombyx mori; CARM-1, coactivatorassociated arginine (R) methyltransferase-1; CoA, coenzyme A; DBD, DNA-binding domain; Ftz-F1, fushi tarazu factor 1; GST, glutathione-S-transferase; LRH-1, liver receptor homolog 1; LXR␣, liver X receptor-␣; MBF-1, multiprotein bridging factor 1; SF-1, steroidogenic factor 1; SHP, small heterodimeric partner; TAF, TBP-associated factor; TBP, TATA box binding protein; TFIID, transcription factor IID.
doi:10.1210/mend.16.6.0843 pmid:12040021 fatcat:tgtqs4ng3rgcbijhqubvk4cjhy