Isolation ofMonoclonal Antibodies Specific forHumanc-myc Proto-Oncogene Product

Sixmonoclonal antibodies havebeenisolated frommiceimmunized withsynthetic peptide immunogens whosesequences arederived fromthatofthehumanc-myc geneproduct. Fiveofthese antibodies precipitate p62C-mYc fromhumancells, andthree ofthese five alsorecognize themousec-mycgeneproduct. Noneofthe antibodies seesthechicken pllW9-mYC protein. Allsixantibodies recognize immunoblotted p62c-mYc. These reagents also provide thebasis foraimmunoblotting assay bywhichtoquantitate p62c-mYc incells. Thehumanc-mycproto-oncogene isthehumancellular homolog oftheavian v-mycgenefound inseveral leukemo- genic retroviruses. Aberrant expression ofthec-mycgene hasbeenimplicated inanumberofneoplasms inavariety of avian andmammalian species. Thehumanc-mycgenehasbeensequenced (4,5,9,25, 27). Fromtheopenreading frameinexons2and3ofthe geneitispossible toinfer theexistence ofa439-amino-acid geneproduct. Fromthis sequence, synthetic peptide immu- nogenshavebeenconstructed. Antibodies raised against these peptides identify thehumanc-mycgeneproduct asa protein withthemobility ofa62-kilodalton (kDa)protein on sodium dodecyl sulfate (SDS)-polyacrylamide gels, p62c-rxc (13, 18,20). Liketheproducts oftheavian v-myc-containing genes, p62c-mY( isassociated mainly withthenuclei ofcells. Probably, then, itiswithin thecell nucleus thatp62cmYc exerts itsnormal andoncogenic functions. Inaneffort toderive better immunological reagents forthe identification, assay, andstudyofmammalian c-mycgene products, we haveisolated sixmonoclonal antibodies (MAbs), eachspecific foroneoftwosynthetic peptides whosesequences areencoded within humanp62cmY(. Inthis report wedescribe thecharacterization ofthese reagents and outline their possible usesintheanalysis ofp62c-mY levels in cells.