title: Structure-function analysis of fos protein: a single amino acid change activates the immortalizing potential of v-fos.
abstract: We have undertaken a detailed structure-function analysis of v-fos protein, taking the ability to induce transformation and immortalization as criteria of biological activity. Our results demonstrate that the evolutionarily conserved center region of fos, comprising ca. 28% of the protein, is indispensable for its function. A single amino acid change (Glu 138----Val 138) in this region activates the immortalizing potential of v-fos without affecting its transforming capacity. The presence of additional either N- or C-terminal amino acids, however, is required for efficient expression of a stable protein, and significantly increases its biological activity. In contrast, sequences in the C-terminal half (between positions 228 and 267) strongly downmodulate the transforming activity of v-fos protein without decreasing its immortalizing potential.
mesh_terms: D000596:Amino Acids; D000818:Animals; D002872:Chromosome Deletion; D004262:DNA Restriction Enzymes; D005260:Female; D015683:Gene Products, gag; D051379:Mice; D009154:Mutation; D011247:Pregnancy; D012191:Retroviridae Proteins / Q000032:analysis*; D013329:Structure-Activity Relationship
chemical_list: D000596:Amino Acids; D015683:Gene Products, gag; D012191:Retroviridae Proteins; D004262:DNA Restriction Enzymes