Myc interacts genetically with Tip48/Reptin and Tip49/Pontin to control growth and proliferation during Drosophila development.
The transcription factor dMyc is the sole Drosophila ortholog of the vertebrate c-myc protooncogenes and a central regulator of growth and cell-cycle progression during normal development. We have investigated the molecular basis of dMyc function by analyzing its interaction with the putative transcriptional cofactors Tip48/Reptin (Rept) and Tip49/Pontin (Pont). We demonstrate that Rept and Pont have conserved their ability to bind to Myc during evolution. All three proteins are required for tissue growth in vivo, because mitotic clones mutant for either dmyc, pont,or rept suffer from cell competition. Most importantly, pont shows a strong dominant genetic interaction with dmyc that is manifested in the duration of development, rates of survival and size of the adult animal and, in particular, of the eye. The molecular basis for these effects may be found in the repression of certain target genes, such as mfas, by dMyc:Pont complexes. These findings indicate that dMyc:Pont complexes play an essential role in the control of cellular growth and proliferation during normal development.
Bellosta
Paola
P
Zoologisches Institut, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich, Switzerland.
Hulf
Toby
T
Balla Diop
Soda
S
Usseglio
Fabrice
F
Pradel
Jacques
J
Aragnol
Denise
D
Gallant
Peter
P
D000818:Animals; D030801:Animals, Genetically Modified; D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D002460:Cell Line; D049109:Cell Proliferation; D004265:DNA Helicases / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D029721:Drosophila Proteins / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics* / Q000254:growth & development* / Q000378:metabolism; D005123:Eye / Q000254:growth & development / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D010641:Phenotype; D011485:Protein Binding; D016271:Proto-Oncogene Proteins c-myc / Q000235:genetics* / Q000378:metabolism
D002352:Carrier Proteins; D029721:Drosophila Proteins; D016271:Proto-Oncogene Proteins c-myc; C486546:rept protein, Drosophila; D004265:DNA Helicases; C504804:pont protein, Drosophila