Figure 2.

A simulation model of the CAV ORF3 protein associated with various binding partners and its different effects on signal transduction pathways. The ORF3 protein can associate with importin β1, which facilitates its translocation from the cytoplasm to the nucleus. In tumor cells, the ORF3 protein phosphorylated by Kinase, interacts with a subunit of APC/C called APC1 and directly interacts with PML to induce the formation of PML nuclear bodies. The NES of the ORF3 protein is functional in a CRM1-dependent fashion in normal but not in tumor cells, which indicates that in tumor cells, the ORF3 protein is unable to be driven out of the nucleus with the NES out of function when CRM1 inhibited. This hypothetical model may not apply to non-tumor cells in 1BR3 normal human diploid fibroblasts and the early passage secondary culture of normal human embryonal lung fibroblasts 6689 (Guelen et al., 2004).