Signal-mediated nuclear transport in simian virus 40-transformed cells is regulated by large tumor antigen.
Transformation of cultured cells with simian virus 40 (SV40), or transfection with the early region of the SV40 genome, causes a significant increase in both the rate of signal-mediated nuclear transport and the functional size of the transport channels (located in the pore complexes). By microinjecting purified large tumor (T) antigen into the cytoplasm of murine BALB/c 3T3 cells, we have demonstrated that this protein alone can account for the increase in transport capacity. The T antigen-dependent changes can be partially inhibited by cycloheximide and require a functional nuclear localization sequence. Although necessary, the nuclear localization sequence by itself cannot produce the observed variations in nuclear permeability and presumably function in a "helper" capacity, in association with another, as yet unidentified domain.
D016475:3T3 Cells; D000818:Animals; D000952:Antigens, Polyomavirus Transforming / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000378:metabolism* / Q000648:ultrastructure; D002472:Cell Transformation, Viral; D007473:Ion Channels / Q000378:metabolism / Q000648:ultrastructure; D051379:Mice; D008807:Mice, Inbred BALB C; D015398:Signal Transduction / Q000502:physiology*; D013539:Simian virus 40 / Q000235:genetics*; D014162:Transfection
D000952:Antigens, Polyomavirus Transforming; D007473:Ion Channels