Characterisation of proteins that bind to FGF1 and to the cytoplasmic part of FGF-receptor 4.

If FGF1 plays an important role inside the cells, it must interact with components in the cytosol and nucleus. Using the yeast two-hybrid system we have earlier cloned a nuclear protein, FIBP, which binds to FGF1 (but not FGF2). We have not been able to assign any other function to this protein. After the sequencing of the Drosophila gene was complete, we have found a homologous protein (43 % homology) in the fly. Hopefully this can lead to some understanding of its function.

Using a fusion protein of FGF1 and maltose-binding protein as a bait, we have identified several proteins from a cell lysate that bind to the growth factor. We have purified these proteins by microsequencing and electrospray mass spectrometry. We have in this way identified two proteins; protein kinase CK2 and ribosom-binding protein p34. These two proteins may be involved in FGF1 intracelluar signalling.

In a similar way we have used the minimal part of FGF receptor 4 that is sufficient to facilitate translocation of the growth factor into cells to identify proteins that bind to it. We will use the same approach to identify these proteins which may be involved in the translocation mechanism.

Nov 17, 2003 Page visits: 2536