The levels of the bancal product, a Drosophila homologue of vertebrate hnRNP K protein, affect cell proliferation and apoptosis in imaginal disc cells.
We have characterized the Drosophila bancal gene, which encodes a Drosophila homologue of the vertebrate hnRNP K protein. The bancal gene is essential for the correct size of adult appendages. Reduction of appendage size in bancal mutant flies appears to be due mainly to a reduction in the number of cell divisions in the imaginal discs. Transgenes expressing Drosophila or human hnRNP K are able to rescue weak bancal phenotype, showing the functional similarity of these proteins in vivo. High levels of either human or Drosophila hnRNP K protein in imaginal discs induces programmed cell death. Expression of the antiapoptotic P35 protein suppresses this phenotype in the eye, suggesting that apoptosis is the major cellular defect caused by overexpression of K protein. Finally, the human K protein acts as a negative regulator of bancal gene expression. We propose that negative autoregulation limits the level of Bancal protein produced in vivo.
Charroux
B
B
Laboratoire de Génétique et Physiologie du Développement, UMR 6545 CNRS-Université, IBDM CNRS-INSERM-Université de la Méditerrannée, F-13288 Marseille Cedex 09, France.
Angelats
C
C
Fasano
L
L
Kerridge
S
S
Vola
C
C
D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis / Q000235:genetics*; D002455:Cell Division / Q000235:genetics*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics* / Q000254:growth & development; D047108:Embryonic Development; D005123:Eye / Q000254:growth & development; D015870:Gene Expression; D005786:Gene Expression Regulation; D017344:Genes, Insect; D005816:Genetic Complementation Test; D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D008969:Molecular Sequence Data; D009154:Mutation; D012261:Ribonucleoproteins / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution; D014764:Viral Proteins / Q000096:biosynthesis; D014921:Wings, Animal / Q000254:growth & development
D029721:Drosophila Proteins; D034641:Heterogeneous-Nuclear Ribonucleoprotein K; D034441:Heterogeneous-Nuclear Ribonucleoproteins; C400301:HnRNP-K protein, Drosophila; D051034:Inhibitor of Apoptosis Proteins; D012261:Ribonucleoproteins; D014764:Viral Proteins; C086430:inhibitor of apoptosis, Nucleopolyhedrovirus