A novel function for Myc: inhibition of C/EBP-dependent gene activation.
We have investigated the effect of the v-Myc oncoprotein on gene expression in myelomonocytic cells. We find that v-Myc dramatically down-regulates the expression of myelomonocytic-specific genes, such as the chicken mim-1 and lysozyme genes, both of which are known targets for C/EBP transcription factors. We present evidence that Myc downregulates these genes by inhibiting the function of C/EBP transcription factors. Detailed examination of the inhibitory mechanism shows that amino-terminal sequences of v-Myc, but not its DNA-binding domain, are required for the suppression of C/EBP-dependent transactivation. Our findings identify a new function for Myc and reveal a novel mechanism by which Myc affects the expression of other genes.
Mink
S
S
Hans Spemann Laboratory, Max Planck for Immunobiology, Freiburg, Germany.
Mutschler
B
B
Weiskirchen
R
R
Bister
K
K
Klempnauer
K H
KH
D000123:Acetyltransferases; D000818:Animals; D022762:CCAAT-Enhancer-Binding Proteins; D002460:Cell Line; D002645:Chickens; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000502:physiology; D015536:Down-Regulation; D005786:Gene Expression Regulation / Q000502:physiology*; D009113:Muramidase / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics*; D016274:Oncogene Protein p55(v-myc) / Q000737:chemistry / Q000502:physiology*; D011506:Proteins / Q000235:genetics; D011784:Quail; D015533:Transcriptional Activation
D022762:CCAAT-Enhancer-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D016274:Oncogene Protein p55(v-myc); D011506:Proteins; D000123:Acetyltransferases; C077509:mim-1 protein, Gallus gallus; D009113:Muramidase