So this is a g coupled protein receptor that actually uses this pathway to regulate the blood pressure inside the cardiovascular system of our body. So we have a primary messenger, a peptide hormone known as angiotensin that binds until angiotensin two receptor and that initiates this phosphonositide signaling pathway. So now let's actually move on to this pathway. And let's begin by examining the structure of this g coupled protein receptor before that primary messenger actually binds onto its site. So we have the membrane, we have the inside the cell, the outside of the cell. On the outside the cell, we have this cavity that basically binds the primary messenger.