Mutations in the genes that code for proteins in this pathway have been linked to various types of cancer (i. e., ras-pancreatic, braf-colorectal, mek-melanoma, egfr-lung). if you were developing a new cancer drug, what would be an appropriate target protein for the new drug therapy?

Ans.

The given proteins, such as EGFR (epidermal growth factor receptor), ras, MEK, and b-raf, are in involved in pathway that stimulates and control cell growth. The epidermal growth factor binds with EGFR that transmits the downstream signals with the help of various cytosolic proteins, as Ras to raf, and raf to MEK. These proteins activate signalling pathways that induce growth and division of the cell, thus, any gain of function mutation in these proteins lead to uncontrolled cell growth and debeloment of cancer.

If a new cancer drug is developed to target this pathway, it should be able to bind with EGFR instead of its ligand EGF. These drugs include monoclonal antibodies against EGFR that block the EGFR-Ras-raf-MEK pathway by inhibiting signal transduction from membrane receptor EGFR to cytosolic proteins and thus, control cell division and prevent tumor formation.

protein synthesis is an example of feedback mechanism which in homeostasis

most community's take hundreds of years to become stable