…Smad4 into a Nuclear Complex with FAST-1
Upon activin stimulation, Smad2 associates with Smad4, accumulates in the nucleus, and interacts with the DNAbinding protein, FAST-1 or FAST2 (reviewed in Attisano and Wrana, 1998; Kretzschmar and Massagué, 1998; Heldin et al., 1997; Whitman, 1998).