Question

Question: A single hormone may initiate different pathways after binding to different receptors on the same cell. Explain how, and give examples?

Answer 1

A single hormone can bind to different receptors and hence trigger the activation of different signaling pathways. The hormones circulate through the bloodstream and hence can bind to the target cell by binding to the hormones. It can activate many pathways because at times a single cell display multiple receptors to which the hormone binds and it activates different response. When a hormone binds to the cell receptor, it can initiate many signaling pathways as it binds to different receptors and hence gradually leads to change in the behavior of target cells. An example is the binding of the estrogen which is a steroid hormone and it passes through the plasma membrane of cell as it is lipid soluble. Within the cells, it binds to specific receptors and hence leads to transcription of genes after the activation of the estrogen-receptor complex. This leads to induction of protein synthesis and this leads to production of receptor which binds progesterone. As the progesterone enters the cell, it is able to bind to the receptor and hence helps the cell to stimulate production of enzymes that helps in nourishing the uterus and prepares for pregnancy.