Hi in this video, I'm gonna be talking about integration of multiple signaling pathways. So signaling pathways do not at all work independently of each other. So they're not linear pathways. Instead they're connected um called signaling networks. They're connected via Crosstalk via interactions via all these different ways. So they can be connected because there's numerous extra cellular signals which all activate different things at the same time. Um protein kindness is activated by one pathway are involved in other pathways. And once those kindnesses are activated they just go on and activate lots of different things whether or not it's in the same pathway. So there's this overlap and then you have crosstalk between second messengers which what that means is that you have the second messengers that are going on but they don't just activate something or pass that message to one, they pass that message to really anything that they have the ability to so they're huge pathways. Now they can be positive and negative interaction. So things like feedback loops or the end product mediates the activity of an earlier product. So this mediation could either activate or stimulate but it could also inhibit. So it would be positive, positive and negative. Um You have these things called feed forward relays and this is where the activity of one component stimulates a really distant downstream component. Um So if something like say product too is like really active, it can go forward and activate Product seven and that would be like really far down a signaling pathway. And so um the signaling networks in the cell are extremely complex which is kind of just the summary of this. So there's 1500 receptors, 700 kindly sponsored cases in around 2000 transcription factors and they all work in interconnected and cross talk anyways. So here's an example of what this looks like. You obviously don't need to know all these abbreviations, but just realize anytime there's text here, this is a different protein making something, doing something, there's all these different receptors and this is just a sample, right? Like I said, there were 1500 receptors and I'm showing 1234567899 of them. So you can imagine how much is going on in the cell at one time with these signaling pathways. It's a freaking crap time. So with that let's now turn the page.
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Okay, so now I'm going to talk about insulin signaling and the reason that I'm doing this is because it's an example of how different things work together um to have a certain function in the South. It's really simplified though. Um So first we're going to focus on insulin and glucose gin and these are two proteins that work together to maintain stable blood glucose sugar level in the sales. So there are two hormones these that I mentioned. So after you eat, there's a ton of glucose and sugar in the bloodstream from the food that you eat. So what this happens is there's a lot of blood or a lot of glucose in the bloodstream. This triggers the production of insulin, insulin then asked to bind insulin receptors. Now once these insulin receptors are activated, this triggers a lot of different pathways. One of these pathways is the protein kinase B phosphor relation is you're gonna trigger vesicles fusion import of glucose into the cell um and other pathways as well. But after you take in all that glucose into the cell, which happens here, your blood glucose levels dropped. And so what happens then is insulin receptors, insulin's not being produced. So the receptors are not being activated and when they're not being activated, the cell then switches on its um increase in the secretion of glucose jen this other hormone, Once this hormone is secreted, this causes it to bind to different receptors and stimulated a variety of other signaling pathways that have to do with blood glucose maintenance. So here's an example of insulin. So you have insulin binds to the receptor. This activates a variety of different pathways. You don't need to know about these pathways, But you can see here that just in this very simple drawing, it results in a ton of different cellular responses just in the process of maintaining this blood glucose level. So complex pathways, even in this simple example. So with that, let's not move on.
When insulin binds to insulin receptors what happens to glucose?