Basic fibroblast growth factor (FGF-2): the high molecular weight forms come of age.

After over thirty years from its discovery, research on basic fibroblast growth factor (FGF-2) keeps revealing new aspects of the complexity of its gene expression as it evolved in the eukaryotic organisms. The discovery of multiple forms of FGF-2 generated by alternative translation from AUG and non-canonical CUG codons on the same mRNA transcript has led to the characterization of a low molecular weight (LMW) FGF-2 form and various high molecular weight (HMW) forms (four in humans). In this review, we discuss the biochemical features and biological activities of the different FGF-2 forms. In particular, we focus on the properties that are unique to the HMW forms and its biological functions.