Conclusions and Future Directions
The decision to proliferate or to enter a non replicating state is one that a cell must continually reassess. This decision is based in part upon the environmental cues encountered, such as the levels of growth factors, the presence of chemotherapeutic drugs, and infection by viruses. Investigations into the molecular mechanisms by which cells control their proliferative response have focused on positive effectors such as cyclins and viral oncoproteins, negative effectors such as tumor suppressor proteins, and signal transduction pathways leading to the transcriptional activation of various genes in particular stages of the cell cycle. Each of these approaches has implicated E2F in the control of cell growth. Although progress towards understanding the E2F gene family has been rapid, and great advances have been made in the last several years, questions concerning the different family members and their role in cell growth control still remain. Several specific questions that remain to be addressed are discussed below.
KeywordsThymidine Kinase Cell Growth Control Viral Oncoproteins Thymidine Kinase Promoter Cellular Promoter
Unable to display preview. Download preview PDF.
- Neuman E, Flemington EK, Sellers WR, Kaelin WG Jr (1994) Transcription of the E2F-1 gene is rendered cell cycle dependent by E2F DNA-binding sites within its promoter. Mol Cell Biol 14: 6607–6615Google Scholar