According to the study, it is showing that cells and organisms evolving complex biochemical circuits; that follow the principles of control theory, millions of years before the first engineer put pencil to paper. As the cells respond to the nutrient, stress, and hormone stimuli by activating complex signaling circuits. Determining how these circuits function is key to understanding cell behavior; and should shed light on the way that cells integrate information and make decisions.
But the study discovering that the coupling of two interconnecting biochemical circuits within a cell the TOR and PKA pathways work like a thermostat to control the growth of cells in response to the availability of nutrients. For decades, it has been known that mutations in both PKA and TOR cause disease; The new research found that each pathway has its own distinct role and teased out exactly how and why the two pathways work together. If TOR and PKA both activate genes that cause cells to grow; and turn on and off in response to nutrients, then why does the cell need both pathways to control growth.
Cells and organisms evolving complex
Cells are constantly adapting to what’s available in their environment. They discovering that when a cell has a steady availability of nutrients, the TOR pathway makes sure the cell chugs along at an appropriate pace. But when a cell suddenly gets rich in a certain nutrient, the PKA pathway shifts into gear and triggers a 25-fold increase in gene production before turning itself off and letting the far more precise TOR controller take over again. Without PKA, TOR’s response to the influx of nutrients would lag.
Often, chemicals must maintain a certain temperature or you’ll end up with unwanted side reactions. So, engineers include a thermostat inside the chemical mixing chamber,”Let’s say the next stage of a reaction is going to create a ton of heat. They use a feedforward control like PKA to quickly adjust the temperature, and then feedback control takes over to keep it steady like TOR.
Proteins and pathways in the cell
For example, an under productive TOR can result in clinical depression. Overactive TOR results in epilepsy, and overactive TOR or PKA results in cancer. The most important take home message is to think about all the different pathways in a cell in this way that is; think about how pathways work together to provide precise control. We won’t be able to design truly effective drugs. The TOR and PKA pathways act as hubs because they are highly connecting to each other, as well as hundreds of other proteins and pathways in the cell.
As a result, when either of these hubs get breaking the whole system goes down; just as we find with the internet. keep trying to figure out how different pieces of the growth control network work together. There are hundreds and hundreds of signaling pathways that are interconnected, but we still do not know how or why they talk to each other. There is just so much we still have to learn.