A TFG-TEC nuclear localization mutant forms complexes with the wild-type TFG-TEC oncoprotein and suppresses its activity.
Human EMCs (extraskeletal myxoid chondrosarcomas) are soft tissue tumours characterized by specific chromosomal abnormalities. Recently, a proportion of EMCs were found to harbour a characteristic translocation, t(3;9)(q11-12;q22), involving the TFG (TRK-fused gene) at 3q11-12 and the TEC (translocated in extraskeletal chondrosarcoma) gene at 9q22. The present study used both in vitro and in vivo systems to show that the TFG-TEC protein self-associates, and that this is dependent upon the CC (coiled-coil) domain (amino acids 97-124), the AF1 (activation function 1) domain (amino acids 275-562) and the DBD (DNA-binding domain) (amino acids 563-655). The TFG-TEC protein also associated with a mutant NLS-TFG-TEC (AAAA) protein, which harbours mutations in the NLS (nuclear localization signal). Subcellular localization assays showed that the NLS mutant TFG-TEC (AAAA) protein interfered with the nuclear localization of wild-type TFG-TEC. Most importantly, the mutant protein inhibited TFG-TEC-mediated transcriptional activation in vivo. Thus mutations in the TFG-TEC NLS yield a dominant-negative protein. These results show that the biological functions of the TFG-TEC oncogene can be modulated by a dominant-negative mutant.
*Laboratory of Molecular and Cellular Biology, Department of Life Sciences, Sogang University, Seoul 121-742, South Korea.
Bobae
B
Lim
Ah-young
AY
Kim
Hee Jung
HJ
Jun
Jungho
J
Kim
D021581:Active Transport, Cell Nucleus / Q000235:genetics; D002467:Cell Nucleus / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D002813:Chondrosarcoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D046912:Multiprotein Complexes / Q000235:genetics / Q000378:metabolism; D009154:Mutation; D018204:Neoplasms, Connective and Soft Tissue / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D019913:Nuclear Localization Signals / Q000235:genetics / Q000378:metabolism; D015514:Oncogene Proteins, Fusion / Q000276:immunology / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D011987:Receptors, Steroid / Q000235:genetics / Q000378:metabolism; D011988:Receptors, Thyroid Hormone / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000235:genetics*; D033921:Vesicular Transport Proteins
D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; D019913:Nuclear Localization Signals; D015514:Oncogene Proteins, Fusion; D011506:Proteins; D011987:Receptors, Steroid; D011988:Receptors, Thyroid Hormone; C490412:NR4A3 protein, human; C096163:TFG protein, human; D033921:Vesicular Transport Proteins