ma sorption of the gene for a of cell division ensures damag

ma sorption of the gene for a of cell division ensures damaged not replicated if Mutations causing def oencies in DNA damage mutations, increased cell division, EFFECTS OF MUTATIONS leading to cance, can resultif the in (al, or not moodaten r normally would be, as in Cell cyde looking at the pathway in (b) explain whether a 1824 signaling pathways that regulate cell division. Both pathways regulate the cell commonly infuencing cancer-causing mutation in a tumor suppressor result from aberrations in pathways, which may be caused gene, such as p53, is more likely to be a recesive or such dominant mutation. ener spontaneous or environmentally triggered 375

Solution

Several cell cycle stimulation pathways involve through growth factor stimulation. PI 3-kinase, Ras, and Myc regulatory proteins are some of them which stimulate the cell division. First growth factor like platelet derived [PDGF] attaches to its receptor in the cell membrane. These receptors are generally G protein coupled receptors. The receptors need enough amounts of growth factors that can stimulate them. Now when the receptors stimulated the cascade starts and then various G proteins’ related follower proteins stimulate. One of them, cytosol proteins, gets enters into nucleus and binds to the DNA. That binding triggers the cell cycle. Mutation in G proteins’ related follower proteins lead to no signaling for the nucleus and hence stops the cell cycle. The mutation stoops the cascade of signaling process.

P53 is a tumor suppressr gene which produces the protein for suppressing tumor related activities in the cell. Tumor causes by uncontrolled growth of cell. If a UV light enters into the nucleus of a cell, it can damage the DNA by ionization. That damage leads to send a signal which stimulates a protein kinase which activates the p53 protein from its proenzyme or inactive form. The p53 protein then enters into nucleus and binds to DNA. That leads to stop the cell cycle process. That is important because of malfunctioned DNA which if survives, may be results into tumor. Mutation in p53 gene cannot stop the process and cell will start to divide uncontrolled.