Structure and function of 14-3-3 isoforms

ESMS of 14-3-3 proteins gave results which are in very close agreement to the theoretical values and verified the presence of N-acetylation. Two sets of sheep and chicken brain isoforms differ in mass by 80 Da. This suggests the presence of phosphorylation in specific isoforms which is conserved across a wide range of species. We are currently identifying this site of phosphorylation which is present specifically on isoforms that have been shown to interact with the oncogene-related protein, c- Raf. Two dimensional gel electrophoretic analysis of truncated 14-3-3 recombinant proteins has enabled us to identify the site of dimerisation at the amino terminus. Crystals of recombinant 14-3-3 and another protein kinase inhibitor (a Zn^2+-binding protein) have been obtained for X-ray structure analysis.