Phosphoinositide GPCR Signaling

So as you guys have probably noticed from our last lesson video when it comes to phosphor Wannasathit GPC are signaling. There's quite a lot for you guys to remember. And so in this video we're going to talk about how to remember the most important components in the mood, most important events in the correct order for phosphor anasazi GPC are signaling. And notice down below we're showing you a little image of phosphor and a ctG pcR signaling with the most important components and the most important events in the correct order. And so of course we know that all GPC are signaling pathways are going to start with a ligand binding to a G. P C. R. More specifically the alpha GPC are in the phosphor GPC are signaling pathway and that's going to cause a confirmation I'll shift in the GPS er that ultimately activates the G. Protein and by activating the G protein. What we mean is that it allows for the G protein to exchange its G. D. P. The low energy inactive form with G. T. P. The high energy active form. Then the G protein alpha sub unit is going to be able to disassociate from the beta gamma subunits and make its way towards the effect er enzyme which in the PSP pathway is phosphor like a C. Or P. L. C then PLC is able to act on its substrate which is pIP two and it can hide relies or cleave pip two into two secondary messengers I. P. Three and D. A. G. I. P three will diffuse through the cytoplasm towards calcium ion channels in the endo plasma particular membrane and it will bind and open those calcium channels so that calcium is released into the cytoplasm, increasing the concentration of calcium in the cytoplasm. And then that released calcium is able to activate cal module in which we have abbreviated here as C. A. M. And then of course the activated cal module in will activate other protein kindnesses which will ultimately lead to the cell response. Now in terms of D. A. G. This is going to remain embedded in the membrane and it's going to diffuse towards the um this other enzyme called protein kinase C. Or P. K. C. And it will activate protein kinase C. Along with calcium that's released from the endo plasma particular. Um and protein kinase C. Is a penis that's able to phosphor relate other targets which also helps lead to the cell response. And so this is quite a lot to be able to remember. But really everything that you the most important features and components and stuff that you need to know is all embedded right here and so down below what we have is a really interesting and unique story that we've come up with here at clutch prep to help you guys remember. Not all of the details but again just the most important components and the most important events in the correct order. And so the plot of our story is that the cell wants to be able to save the day and saving the day is going to represent the cell response. And so the cell wants to be able to save the day from this evil villain named pip and his two web. And so pip and his two weapons is going to represent pip two. And so notice that pip two is right here in this position in our signaling pathway and recall that pip two is going to be the substrate of the effect er enzyme faso like pacey. And so if you'll notice down below, we are numbering the steps of our stories steps number one through seven. And the numbers here in the steps of our story correspond with the numbers that you see up above in this image as well as the numbers that you see down below in this image as well. And all of these numbers correspond with the numbers from our previous lesson, video on the steps of the PSP pathway. And so of course in the very first step of our story, we need to have the ligand binding to the G. P. C. R. And the ligand binding is going to be represented by a lightning strike. And so you can think that the L. And lightning strike is for the L. In ligand binding. And so this lightning strike is going to provide a warning of danger that this evil villain pip and his two weapons are around causing havoc. And so if we take a look at our image down below, notice once again we have our biological membrane right here in the middle and above the membrane we have the outside of the cell and below the membrane we have the inside of the cell. And so notice that on the outside of the cell we have this lightning strike and the lightning strike once again represents the ligand binding to the G. P. C. R. And so when the ligand binds to the GPC are we know that it will cause a confirmation all shift and that confirmation I'll shift will activate the G. Protein, the hetero try Merrick G protein that has three different subunits that are once again being represented by this Alpha Hero which represents the alpha subunit, the beta blaster which represents the beta subunit and the gamma gadget which represents the gamma subunit. And so notice that this Alpha Hero notices the evil villain pip and his two weapons over here. So notice that pip looks like a bank robber and he's got these two weapons, this dagger weapon right here as well as these three ice picks that are sticking off. And so the Alpha Hero sees that pip and his two weapons is very are very dangerous. And so the Alpha Hero knows that he's going to need some backup. He's going to need some help to take care of this evil villain pip two. And so he knows that he's going to need to get the police involved. And the police in this image is going to be representing the defector enzyme Pacey. And so once again, when the ligand binds to the G. P. C. R, it will activate the G protein. And that is going to require the GTP exchange. And so that's exactly what our second step of the story is. The alpha Hero or the G protein, alpha sub unit is going to perform the GTP exchange. And so it's going to do that by exchanging the empty siren battery with the full siren battery so that they can sound the alarm and warn the police and get the police involved. And so if we take a look at our image down below, uh notice that our alpha Hero over here and the G protein are going to be associated with a low battery, um, siren, an empty battery siren. Uh and so what you'll notice is that the empty battery here is not going to be able to sound the alarm. And so this empty battery is associated with the G. D. P. The low energy G. D. P. And so the alpha hero is going to exchange the batteries for the siren with a full battery. And so you can see over here, we have the full battery on the siren so that the siren can go off and alarm the police and the full battery is going to be associated with G. T. P. The high energy form. And so of course in step number three the alpha hero is going to alarm the police. And again the police is going to be representing uh fossil like pacey. However when the alpha hero goes to alarm the police, he actually forgets his beta blaster and his gamma gadget behind. And so this reminds us that the G protein alpha sub unit is the only sub unit to dissociate towards the fossil like pacey affect er enzyme. And so if we take a look at our image down below notice that in step number three it's only the alpha hero, only the alpha subunit of this G protein that dissociates towards the effect er enzyme page C. Or the police here and the beta blaster and the gamma gadget are going to get left behind. And again now that the alpha hero has dissociated and has the full battery on the siren, he can alarm the police or the effect of enzyme phosphor like a C. And so in step number four the alpha hero or the G protein alpha sub unit is going to tell the police to target pips to weapons or target pip two. And this is going to represent the activation of phosphor like pacey. The activation of the police to get the police involved. And so what you'll notice is down below the alpha hero and his siren have alarmed the police and told the police what to target Ellen pip two. And again it's gonna be targeting pips to weapons because that's the most dangerous part of pip. And so this represents the activation of phosphor like pacey the activation of the police. And so in step number five the police is going to be taking the advice from the alpha hero and the police is going to Taser pips to weapons and when they Taser pips two weapons, it separates the two weapons into the two secondary messengers. The dagger or the D. A. G. Secondary messenger as well as the three ice picks. And the three ice picks is going to represent I. P. Three. And so what you'll notice is taking a look at pit two. He has two weapons. He's got the dagger portion of his weapon and then he's got these three ice pick sticking off. Now the three ice picks represents I. P. Three. And the dagger of course is going to represent the secondary messenger D. A. G. And so in step number six the three ice picks or I. P. Three is going to drop down to the membrane of the endo plastic particular. Um to release Captain marvelous and Captain marvelous is another hero that's going to be helping to save the day. And again saving the day is going to represent the cell response. And so Captain marvelous is going to help trigger the cell response. And so Captain marvelous here as you can see with the C. A. And the M here being highlighted is going to represent calcium release and cal module in activation and recall cal modular is abbreviated as C. A. With an M. Just like this. And so of course calcium release and cal modular activation is going to lead to the cell response. And again the cell response is going to be indicated by saving the day. And so if we take a look at our image down below, once the police have Taser pips two weapons pits two weapons separate into the two secondary messengers. It separates into the ice pick three or the three ice picks which is going to represent I. P. Three and I. P. Three is going to drop down to the membrane of the endo plasma particular. Um and it's going to affect this calcium channel in the end a plasmid particular. Um and it's going to allow Captain marvelous to exit from the inside of the endo plasma, particularly into the cytoplasm. And so the exiting of this. Captain marvelous is going to be representing the release of calcium and the activation of cal module in. And again this is going to lead to the activation or I'm sorry this is going to lead to the cell response or it is going to lead to saving the day. Now again uh when the police Taser pips two weapons, not only does it produce the ice pick three, but it also is going to produce the D. A. G. Secondary messenger. the dagger. And that dagger is going to flip towards a packed crowd of Spectators that are just watching this whole thing go down. And so this packed crowd of Spectators is going to represent the enzyme P. K. C. And so what you'll notice is that down below we have this packed crowd of Spectators that have been watching this whole thing go down, watching the police taser the weapons and all that stuff. And so this um dagger part is going to flip through the membrane. And what's going to happen is the packed crowd is going to catch that dagger and then use that dagger to generate a cell response. Or in other words to save the day. And so going back here again the dagger flips towards this packed crowd who catch the dagger and use the dagger to help save the day. And again this represents P. K. C. Activation and that P. K. C. Activation will lead to the cell response. And so this is kind of a crazy story but it is not full proof. So there are some holes in this story. However uh this story can help a lot with remembering the most important components and the most important events in the correct order. And so if you go through this silly story a few times you'll be able to remember the most important components and the most important events. And so hopefully this story will help you in some way and we'll be able to apply these concepts as we move forward, so I'll see you all in our next video.

in this video, we're going to introduce the three Fosca anesthetized secondary messengers. And so the PSP pathway or the phosphate and NASA tied signaling pathway, generally involves the production of three secondary messengers that we have numbered down below right here. And so the very first secondary messenger is a NASA tal 145 triphosphate or I P three for short. And so the I is going to be for the I in a non settle, the P will be for the P and phosphate. And of course, the three here will be for the three phosphate groups that are in positions of 14 and five. And so, if we take a look at our image down below over here on the left hand side, notice that we're showing you the structure of a NASA tall 145 triphosphate right here. And so if we were to number these carbons, this would be carbon 123 This is carbon four, and this is carbon five. And so notice that it is indeed carbon one carbon four and carbon five that have these phosphate groups on them. And that's why it's 145 triphosphate, or again, I p three for short now moving forward in our course, we're going to show I p three in this format that you see over here so important to start to recognize how will be showing this particular secondary messenger i p three moving forward in our course. Now, the second type of secondary messenger that is going to be produced is one to die Aysal, glycerol or D A G for short coming from the dye Aysal glycerol. And so, if we take a look at this structure down below right here, what you'll notice is that this is actually a glittery all attached to to fatty acids. And so notice that the glycerol is this, uh, structure right here and the two fatty acid chains would be These are groups that are essentially Esther linked right here. And so we're going to represent our diocese glycerol as this structure right here, moving forward in our course, this red looking structure. And so the diesel glycerol again can be commonly abbreviated as just d a g or dag. Now, the third and final secondary messenger are calcium ions or see a two plus. And so over here on the far right, We're showing you guys some calcium ions. Now, one thing to note is that this structure and this structure may already look somewhat familiar to you guys from our very last lesson video. And that's because notice that these two structures actually come from the foster title in as little 145 this phosphate or pip to that we introduced in our last lesson video. And so you could see that the Dag molecule is right here and the I P three molecule is right here. And so really, these two secondary messengers, which will see moving forward in our course, is that they're coming directly from Pip to. And so that's one thing to keep in mind as we move forward in our course. But for now, this year concludes our introduction to the three phosphate unassisted secondary messengers, and we'll be able to see the exact rolls of each of these three moving forward in our course. So I'll see you guys in our next video

in this video, we're going to introduce the steps in Foss Vagina Ctg PCR signaling. Now it turns out that there are actually many different variations of fossil and NASA tied signaling pathways or PSP pathways. However, all of these different variations can be condensed into eight general steps that we have listed and number down below and our image. So you can see the first three steps are right here, then steps four through seven are right here and yellow and step number eight is way down below this large image right over here. And so what's important to note is that some of these steps are associated with a gray color like what you see here. And these steps are very, very similar toe what we've seen before and the A dental it cyclist GPC our signal transaction pathway and then notice that other steps are numbered with these yellow numbers. And that's because these steps are really, really specific and pretty much brand new and the PSP pathway. And so we've color coordinated it like this to help you guys organize the information a little bit better. And so taking a look at this first set of three steps right here, which again are color coded in gray. So they're pretty much the same as before. We're labeling this as the Alfa Adrianne ergic pathway because ultimately these first three steps right here lead to the activation of the Alfa Adrianne ergic. GPC are and so and step number one, what we have is the hormone signaling lie gand again. Epinephrine or some other hormone potentially as well could bind to the GPC are more specifically in this PSP pathway again the Alfa agin ergic G PCR or receptor. And that's going to cause a confirmation. All shift and the structure of the GPC are just as we've seen before in the a dental it cyclist GPC are signaling pathway. Then in step number two again, this GPC our confirmation will shift is going to activate the g protein. And again the G protein in the PSP pathway is abbreviated as G Q and so the GPC Our confirmation will shift activates geek by again promoting the Alfa Sub unit to exchange G D. P with GTP and then in step number three again with the bound GTP. The Alfa sub unit of G Q is going to disassociate from the Beta gamma sub units on diffused towards a nearby affect, er, enzyme. And, of course, the effect er enzyme is going to be different in the PSP pathway. It will not be a dental, it cycles. Instead, it will be phosphor like Pacey, as we'll see here very shortly. But let's take a look down below at our image just to take a look at the first three steps, which again is pretty much review from our previous lesson videos. And so notice that steps one, two and three are labeled right here with these gray numbers that we see. And so again, and step number one, the hormone signaling like an epinephrine will bind to the GPC are more specifically, the Alfa agin ergic GPC are causing a confirmation. I'll shift in that G p c. R. And that confirmation I'll shift is going to activate the hetero try Merrick G protein that we have down here essentially promoting it to exchange its GTP, um, and use the GDP to replace the G. D. P. And so the Alfa sub unit with the bound GTP of G Q is going to disassociate towards, uh, the affect er, enzyme here, and really, this leads us to our first relatively new step here in step number four. So if we go back up to our text, we can see that this is really the beginning of the PSP pathway, the fossil unassisted signaling pathway. And so, in step number four, the activated GTP bound Alfa sub unit of G Q not only is going to disassociate towards the effect er, enzyme, but it's also going to bind and activate that affect, er, enzyme as well. And again, the effect er enzyme in the PSP pathway is not a dental it cycles. Instead, it's going to be phosphor, a light pace, see or PLC for short. And so, if we take a look at our image down below right here in step number four, notice that the Alfa sub unit of the G protein G Q. With the bound GTP, is going to activate the effect er enzyme right here, which again is going to be pro fossil like PC PLC. And that leads us really to step number five, which we can see down below right here. So if we go up to our text notice that end step number five The Activated PLC is going to hide, relies its substrate and its substrate is going to be phosphate title Enos it'll four or five This phosphate which we know is going to be pip to and so pip to when it is hydrolyzed it's going to generate to secondary messengers. And so essentially, what we're saying is that this active PLC, it's going to cleave pip to, uh, to generate two additional secondary or to secondary messengers. And those two secondary messengers are going to be I, p three and D A. G or DAG. And so, if we take a look down below at our step number five, which is right here, which will notice is that the Active PLC is right here in the membrane and pip to is right here. And so again, PLC is going to cleave pip to or hydrolyzed pip two and essentially generate thes two secondary messengers down below. What we have is I p three, which we can label right here I p three and then up above, still embedded within the membrane. What we have is d a g day so glycerol here and so again what you will notice is that the I P three is a side of Solich molecule that can diffuse through the cytoplasm. And so it's making its way downwards into the side of Saul of the cell, whereas D. A G, on the other hand, is still embedded within the cells plasma membrane. And so it's not actually able to diffuse into the cytoplasm. It's on Lee able to defuse laterally left and right here. And so that's gonna make a big difference. And you can also see that this step number five is going to cause a split in our pathway where we're going to need to follow I p three and see what it does. But then we're also gonna need to come back and follow D A. G and see what it does in the memory. So first, we're gonna start off and step number six, as you can see here, following i p three and its diffusion into the cytoplasm. And so in step number six, what you can see is that I p three, the secondary messenger, is going to defuse further into the cytoplasm towards the end of plasma. Ridiculous. Um, in order to bind and open calcium. See a two plus transport channels that are embedded in the end, a plasmid ridiculous. And ultimately, when it opens these transport channels, it's going to allow all of the calcium that stored in the end of plasma particular, um, to be released into the cytoplasm. And so this is going to cause a drastic increase inside a solid calcium concentration. And then, ultimately, the increased calcium in the cytoplasm is going to be used to activate another protein that's known as Cal Module in abbreviated as C A. M like so. And we'll talk a lot more about Cal module in later in our course. But for now, bear with me here, and so the calcium will activate Cal module in. And then the calcium Cal module in Complex is going to move on to activate other side of Solich proteins and that ultimately site a solid protein, kindnesses or enzymes that fox for late things. And ultimately this is going to lead to the cell response. And so if we take a look down below at our step number six, notice that I p three is right here and again in step number six. It's going to diffuse and bind to a calcium ion transport channel in the end of plasmid particular membrane. So this memory that you see down below right here is the e r. Membrane. And so it has this calcium channel inside of it, and I P three is binding to an opening this calcium channel so that all of the calcium that's packed inside of the end of plasma ridiculous um, can actually be released into the cytoplasm. And so the calcium concentration in the cytoplasm, as we indicated up above right here, is going to increase. There's going to be an increase inside a solid calcium concentration. And then this calcium that is released into the cytoplasm will be able to activate the Cal module in, and the calcium Cal module and complex will be able to activate other protein kindnesses and these protein kindnesses ultimately lead helped lead to the cell response. And again, that's exactly what we described up above in our text. So now that we followed I p three all the way through to this cell response, we need to go back and check out what d a G is doing here in the membrane and that is really what Step number seven it's all about. So if we go back up to our text and step number seven, notice that in step seven D a g d isil glycerol is going to diffuse in the membrane and along with that released calcium from Step number six, it's going to activate a membrane bound protein kind A, C or P K C for short. And so, if we take a look down below right here at our step number seven in our image, notice that D A G again is membrane bound so it can Onley diffuse in the membrane laterally. And so we have lateral diffusion here where D A G could defuse towards this other enzyme over here, called P k C protein kind E C and protein kinase C is another kind knees that can go onto Fox for early its targets and helped lead to the cell response and notice that the calcium that was also released by Step Number six can also be used here to help activate the P K C along with D A. G. And together they help activate P K C. To generate the cell response And so this leads us to step number eight, which is way down below right here and notice. Step Number eight is color coded in gray, so it's very similar to a previous step from the A dental It Cyclist G PCR pathway and in step number eight. What's important to know is that the G protein Alfa sub unit of Geek Again is going to have GTP ace activity. So it's going to slowly inactivate itself along with the effect er enzyme PLC again by hide relies ing, it's GTP, the high energy active form into the low energy inactive form G. D. P. And so this will allow the Alfa Sub unit to reassemble its original inactive form with the Beta gamma sub units and then the like and can disassociate from the GPC are to reset the pathway. And so, if we take a look at our image up above, notice that step number eight we actually have down below in this tiny little side image. And so what you'll notice is that the GTP hydraulics ISS function of the G protein Alfa sub unit is going to come into play, and so it's going to cleave GTP, the high energy active form into the low energy inactive G D P form. And then the Alfa sub unit will be allowed again to reassemble its original confirmation with the Beta Gamma sub units. And then, of course, the lie again epinephrine can disassociate from the GPC are to help reset this entire pathway. And really, this is it. These are the eight steps to the PSP pathway. And after you guys get some practice going through these steps, it'll come a little bit more naturally. But there is quite a lot here for you guys to remember. So in our next video, we're going to be able to talk about a memory tour in a story that you can use toe help. You guys effectively remember the most important components and events in the correct order. So I'll see you guys in our next video

So as you guys have probably noticed from our last lesson video when it comes to phosphor on a CTG PCR signaling there's quite a lot for you guys to remember. And so in this video, we're going to talk about how to remember the most important components and the most important event in the correct order for phosphate and Assata. GPC are signaling and notice down below. We're showing you a little image of fossil in a city. GPC are signaling with the most important components and the most important events in the correct order. And so, of course, we know that all GPC are signaling pathways are going to start with a ligand binding to a G p C. Are more specifically, the Alfa agin ergic GPC are in the phase velocity. GPC are signaling pathway that's going to cause a confirmation. I'll shift in the GPC are that ultimately activates the G protein and by activating the G protein, what we mean is that it allows for the G protein to exchange its G d p, the low energy inactive form with G T p, the high energy active form, then the G protein Alfa sub unit is going to be able to disassociate from the Beta gamma sub units and make its way towards the effect er enzyme, which in the PSP pathway is Foss follow like pay C or P L C. Then PLC is able to act on its substrate, which is pip to, and it can hide, relies or cleave pip two into two secondary messengers. I p three and D A G I p three will diffuse through the cytoplasm towards calcium ion channels in the end of plasma particular membrane, and it will bind and open those calcium channel so that calcium is released into the cytoplasm, increasing the concentration of calcium and the cytoplasm. And then that release calcium is able to activate Cal module, in which we have abbreviated here s C A M. And then, of course, the activated Cal module in will activate other protein kindnesses, which will ultimately lead to the cell response. Now, in terms of D A G, this is going to remain embedded in the membrane, and it's going to defuse towards the um, this other enzyme called protein kinase C or P K. C. And it will activate protein kinase C along with calcium that's released from the end of plasma ridicule. Um, and protein kinase C is a kindness that's able to phosphor late other targets, which also helps lead to the cell response. And so this is quite a lot to be able to remember. But really everything that you the most important features and components and stuff that you need to know is all embedded right here and so down below. What we have is a really interesting and unique story that we've come up with here, a clutch prep toe. Help you guys remember not all of the details, but again just the most important components and the most important events in the correct order. And so the plot of this story is that the cell wants to save the day, and saving the day represents the cell response. And you can see the cell responses right here in our pathway. And so the cell wants to save the day from this evil villain named Pip the Troll and his two weapons. And so Pip and his two weapons represents pip to from our pathway up above. And so what you'll notice is down below. We are numbering the steps from our story and the numbers that you see here in the steps of our story correspond with numbers from our last lesson video for the steps of the PSP pathway and down below. We have this really interesting image where again we're symbolizing the hetero try Mary G Protein as the Hulk and his two brothers And then over here, what we have is Pip the Troll, which is an actual marvel villain. If you Google pip the troll, you'll see that I did not make up this villain. And so Pip the troll over here actually has two weapons. As we already indicated. He's got this dagger and then he's also got these three ice picks that emerged here together. And so, in the very first step of our story, of course, we know that GPC our past pathways start with the ligand binding. And so in our story, the ligand binding is going to be ah, lightning strike, providing a warning of danger. And so if you take a look down below, notice that we have this lightning strike here which is really again providing a warning of danger and a warning that this evil villain pit to is actually around, causing havoc. And so again, the lightning strike here represents the ligand binding to the GPC are. And then, of course, we know that the G p. C R will undergo a confirmation, will shift and ultimately activate the hetero try Merrick G protein by causing it to essentially exchange it's g g d. P with GTP. And so in step number two, what we have is the GTP exchange and so are Alfa Male, which is again clearly going to be the hawk down here. The hawk is going to be the Alfa Male because notice the Beta and Gamma brothers are definitely not gonna be Alfa males. And so the Hulk Alfa male here again, he's going to decide to take charge. And which will notice is that the Alfa Male? He detects the danger and he sees Pip to over here from a distance. But he also sees that he has thes two weapons. And so the Hulk is not stupid. And he's like, You know what? This is a little bit too dangerous for me to do on my own, So he's like, I gotta go sound the alarms and get the police involved. And so what you'll notice is that step number two is that the Alfa male, which is again the G protein alphas of unit, is going to exchange the batteries of the siren. So he exchanges the empty siren battery with the full siren battery in order to alert the police. And so this represents the GTP exchange. So down below in our image, noticed that the siren battery over here is empty. So we have this empty battery which represents G, d. P. And, of course, the Hulk. Here, the Alfa Male is going to swap out the battery over here with a full battery so that the alarm can actually go off and sound the police. And so moving on to step three of our story noticed that the Alfa male actually leaves. He dissociates from the Beta gamma sub units and he leaves with that sounded alarm again to alert the police. And you can see here that he alarms the police and the police actually represents Foss Photo light pay c p l C. As you can see here the PLC and fossil like Pacey. And so this alarming of the police represents again the dissociation of the G protein Alfa sub unit and so down below noticed that the police has been alarmed in our step number four here and so down on step number five. What we have is now that the police have been alarmed of Pips presence and his two weapons. The police decided to shoot the most dangerous part of pit, which is his two weapons. They shoot pips to weapons and when they shoot pips to weapons or pit too, uh, they separate them into the two secondary messengers the dagger or the D A G and the three ice picks or I p three and so D A G in the dagger represents diacetyl glycerol, and the three ice picks represents I p three production. So down below, what you'll notice is in our step number five. The police is actually shooting the two weapons here and again separating the two weapons into their two components the three ice picks down below that emerged together and the dagger that we see over here. And so notice that end step number six, which is right here, uh, that the three ice picks are going to drop to release Captain America Toe Help Save the day And Captain America actually represents calcium release and Cal module in activation again. And that's going to lead to the cell response. The saving the day again is going to represent the cell response. And so notice down below that the ice the three ice picks ice pick three are going to drop Thio, the calcium channel here to release Captain America and Captain America here again represents calcium release and Cal module in activation, which leads to the cell response. And then, of course, in step number seven up above. Which will notice is that when the police shoot that those two weapons, the dagger part flips towards a packed crowd of Spectators that air watching this whole thing take place and the packed crowd of Spectators represents P K. C. And so the packed crowd of Spectators or P k c catch that dagger and help save the day. And so this represents P K C activation and again the cell response. And so in step number seven, notice that we have this packed crowd of Spectators that we're watching this whole thing go down watching the police shoot pips, weapons. And, of course, that dagger part flips through the membrane. Over here, the packed crowd catches it, and together this helps save the day and generate the cell response. And so really here. This is not a perfect full proof story. However, If you're able to get this story down pack, then you'll be able to again put all of these important components and events into the correct order, and you'll be able to get the fossa in a city. GPC are signaling pathway down, No problem. And so you just need to run through this story just a couple of times and you guys will be good. And so we'll be able to get some practice applying these concepts as we move forward in our course, so I'll see you guys in our next video.

All right. So here we have an example problem that wants us to place the following steps of the PSP signaling pathway down below right here in the correct order from step one to step seven. And so, of course, what we need to recall is that the PSP pathway or the Foss PFOA nossa tied signaling pathway is a GPC are signaling pathway. And of course, GPC are signaling pathways. Begin with the ligand. Binding to the GPC are itself and so we can go ahead and put this as our step number one. And of course, we know that the lie again binding to the GPC are is going to cause a confirmation Will shift in the g p c r and the confirmation I'll shift in the GPC our ends up causing a confirmation I'll shift of the G protein, allowing it to exchange its GDP for GTP more specifically the Alfa sub unit of the G protein And so this will be our step number two And then, of course, at that point, once the G protein is activated, the Alfa sub unit of the G protein is going to disassociate from the beta gamma sub units of the G protein. And so this will be step number three. And then, of course, we know that the Alfa sub unit of the G protein that has dissociated is going to defuse towards an effect er, enzyme more specifically, phosphor, a light pay see. And it's going to activate fossil like Pacey. And so that is going to be step number four. And then, of course, we know that the substrate of fossil like Pacey is, uh, pip to. And so what will happen next is that fossil like Pacey is going to hide, relies its substrate pip to and convert it into the two secondary messengers I, p three and D A g dag. So this will be our step number five here. And then, of course, at that point, we know that we need to follow I p three and D A g separately. Since I p three is gonna be cida Solich and diffuse into the side of Saul, whereas D A G is going to remain membrane bound and can Onley diffuse laterally within the membrane. And so if we follow I p three, then the next step is that I p three is going to diffuse through the cytoplasm to the end of plasma ridiculous membrane and bind to calcium channels where it can induce the release of calcium into the cytoplasm, increasing the cytoplasmic calcium concentration. So this will be step number six here. And then, of course, last but not least, our step number seven will be right here. And that is that the diocese glycerol or D a g here, along with the calcium ions that were released, are going to activate protein kind A, C or P K c. And again, this will be step number seven. And so these are really the answers to this practice problem, and that concludes this practice. So I'll see you guys in our next video.