Modulation of EWS/WT1 activity by the v-Src protein tyrosine kinase.
Desmoplastic small round cell tumor (DSRCT) is a malignant human cancer that is associated with a specific t(11;22) chromosome translocation, where 265 amino acids from the EWS amino-terminus are fused to the DNA binding domain of the WT1 tumor suppressor gene. We have noticed the presence of several SH3 interacting domains within the amino-terminus of EWS and have assessed the potential of EWS/WT1 to interact with such motifs. We find that EWS/WT1 can associate with the SH3 domain of several proteins, including v-Src. Ectopic expression of v-Src phosphorylates EWS/WT1 in vivo, as well as enhances the transactivation ability of the EWS amino-terminal domain. Structural alteration of the v-Src SH2 or SH3 domains produced mutants that could not interact with EWS/WT1 nor augment the transcriptional properties of EWS. Taken together, our results suggest the possibility that some transcriptional properties of EWS/WT1 may be regulated by a cytoplasmic signaling pathway.
Kim
J
J
Department of Biochemistry, McGill University, McIntyre Medical Sciences, Montreal, Que., Canada.
Lee
J M
JM
Branton
P E
PE
Pelletier
J
J
D020816:Amino Acid Motifs; D001665:Binding Sites; D002460:Cell Line; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D015688:Oncogene Protein pp60(v-src) / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015514:Oncogene Proteins, Fusion / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation; D019000:Phosphotyrosine / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion / Q000235:genetics; D015398:Signal Transduction; D015533:Transcriptional Activation; D014162:Transfection; D018909:src Homology Domains
C106032:EWS1-WT1 fusion protein, human; D015514:Oncogene Proteins, Fusion; D011993:Recombinant Fusion Proteins; D019000:Phosphotyrosine; D015688:Oncogene Protein pp60(v-src)