Interallelic complementation among DER/flb alleles: implications for the mechanism of signal transduction by receptor-tyrosine kinases.
The large number of available embryonic lethal alleles in the Drosophila EGF receptor homolog (DER)/faint little ball locus allowed us to test the possibility of positive or negative interactions among different DER alleles. These interactions were monitored by examining the embryonic cuticular phenotypes of different heteroallelic combinations. Several positive interactions were identified, while negative interactions were restricted to a single allele. This is the first example of positive interactions within the same cell type among alleles of a receptor tyrosine kinase gene. The basis for these interactions is likely to arise from the mechanism of signal transduction by receptor tyrosine kinases, which involves receptor aggregation. A combination of two different DER mutant proteins defective in temporally distinct stages of the signal transduction process, may thus form a functional heterodimer. The mutation sites in four alleles showing positive interactions were localized. They identify regions within the protein which are likely to be important for these temporally distinct signal transduction processes.
Department of Molecular Genetics and Virology, Weizmann Institute of Science, Rehovot, Israel.
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D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004252:DNA Mutational Analysis; D004330:Drosophila / Q000187:drug effects / Q000196:embryology / Q000235:genetics*; D066246:ErbB Receptors / Q000235:genetics* / Q000502:physiology; D005020:Ethyl Methanesulfonate / Q000494:pharmacology; D005804:Genes, Lethal / Q000235:genetics; D005816:Genetic Complementation Test; D046911:Macromolecular Substances; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D010766:Phosphorylation; D015398:Signal Transduction / Q000235:genetics / Q000502:physiology*
D046911:Macromolecular Substances; D005020:Ethyl Methanesulfonate; D066246:ErbB Receptors