title: Viral and cellular fos proteins are complexed with a 39,000-dalton cellular protein.
abstract: The structure of viral and cellular fos gene products and their association with a 39,000-dalton cellular protein (p39) were investigated by using antisera raised against synthetic peptides. The first peptide, termed M, corresponded to amino acids 127 to 152 of the v-fos sequence, a region which is identical in c-fos. The second peptide, termed V, corresponded to the nine C-terminal amino acids of v-fos; this region is not present in c-fos. Rabbit antisera were purified by affinity chromatography against their respective peptides before being used for immunoprecipitation. M peptide antisera precipitated p55v-fos and p55c-fos, whereas V peptide antisera precipitated only p55v-fos. This observation confirms the prediction from nucleotide sequence analysis that these proteins are distinct at their C termini. p39 was precipitated in association with p55v-fos and p55c-fos by M and V peptide antisera. However, V peptide antisera did not precipitate p39 from cells expressing p55c-fos, even though the presence of p39 in such cells was demonstrated with M peptide antisera. Denaturation of cell lysates completely abolished the precipitation of p39, whereas the precipitation of p55v-fos was unaffected. Taken together, the data demonstrate that p39 exists in a complex with p55.
mesh_terms: D000650:Amnion / Q000378:metabolism; D000818:Animals; D000918:Antibody Specificity; D002467:Cell Nucleus / Q000378:metabolism; D006224:Cricetinae; D007158:Immunologic Techniques; D051379:Mice; D008970:Molecular Weight; D009857:Oncogenes; D011485:Protein Binding; D014764:Viral Proteins / Q000276:immunology / Q000378:metabolism*
chemical_list: D014764:Viral Proteins