Question

4. Imagine a G-protein linked receptor that responds to an external signal that tells the cell to undergo cell division. Suppose that there is a mutation so that the G-protein linked to this receptor is unable to degrade the GTP attached to it to GDP. (That is, once the G-protein is bound to GTP, it stays that way, instead of converting the GTP to GDP after time has passed.) What would you predict would happen in the cell? Do you think this mutation would an example of a tumor suppressor mutation, or a oncogene mutation? Please explain your answers.

Answer 1

This G-protein will remain active and will keep in cell the pathway of cell division continuous. The will keep the cell on dividing and will give rise to the tumor.

This mutation would be the example of the oncogene because the gene mutated was responsible for providing the cell signal for its division and now this gene is not regulated and leads to tumor, where as tumor suppressor mutation occurs in the gene which codes for the protein which checks the cell division when the cell is not ready to divide due to some reasons like DNA damage. This gene leads to apoptosis of the cell which may lead to tumor formation. Example of tumot suppressor protein is p53 protein.