| FIF [ fibroblast growth factor 2 ( FGF 2 ) interacting factor ] , a nuclear putatively antiapoptotic factor , interacts specifically with FGF 2 . ^^^ Through the screening of GAL 4 based yeast two hybrid expression libraries , we have isolated a gene encoding a nuclear protein of 55 kDa , FIF ( FGF 2 interacting factor ) , which interacts specifically with FGF 2 but not with FGF 1 , FGF 3 , or FGF 6 . ^^^ In this system , FIF interacts equally well with the NH 2 extended 24 kDa FGF form as with the 18 kDa form , indicating that the FIF binding motif is located in the last 155 amino acids of FGF 2 . ^^^ The region spanning these repeats is , together with a region located in the N terminal part of the FIF protein , implicated in the binding to FGF 2 . ^^^ Thus we discuss the possibility that these activities could reflect a physiological function of FIF through its interaction with FGF 2 . . ^^^ |