DOMINANT-NEGATIVE MUTANTS - TOOLS FOR THE STUDY OF PROTEIN FUNCTION IN-VITRO AND IN-VIVO

Powerful new approaches for the identification and sequencing of novel cDNAs have produced a backlog of proteins seeking functions. Traditio nal approaches for characterizing protein function (e.g., blocking mon oclonal antibodies and heterologous expression) have significant limit ations, especially in identifying the roles specific proteins play in vivo. An alternative approach is to engineer mutations in the protein of interest that abolish its function and that also inhibit the functi on of simultaneously expressed wild-type protein (dominant negative mu tations). This approach has wide application to the study of a number of different kinds of proteins but tends to be most effective for prot eins that need to assemble into multimers to be functional. Dominant n egative mutants have already provided insights into the molecular mech anisms of action of a number of protein families, including hormone re ceptors, oncogenes, and growth factor receptors, and have been identif ied as the cause of at least a few autosomal dominant diseases. Expres sion of dominant negative mutants under the control of highly active l ung cell-specific promoters holds great promise for the study of the r oles specific proteins and protein families play in lung development, health, and disease.