ACTIVINRESPONSE FACTOR

Induced in early Xenopus blastomeres by activin, Vg-1 and TGF b, binds to activin-response element in the mix-2 homeobox gene. The ARF complex contains XMAD2, a Xenopus homologue of the Drosophila Mad gene product, and FAST-1, a winged-helix transcription factor.