1
concept
Ubiquitination
5m
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in this video, we're going to introduce Ubiquity Nation, so ubiquitous in is actually a small protein. It's actually a highly conserved and a very prevalent or ubiquitous small protein. And that's exactly where ubiquity in gets its name from, because ubiquitous is so ubiquitous that it's pretty much found in every eukaryotic organism, from yeast all the way up through humans and so ubiquitous in this small, ubiquitous protein. Onley contains 76 amino acid residues and so ubiquitous nation. It's just a process that involves the Covalin attachment of these ubiquity in peptides to a target protein and so ubiquitous nation is also an energy intensive process or an p dependent process, which means that it utilizes energy in the form of a teepee in order to co violently attached thes ubiquity in peptides to the target protein. And so, if we take a look at our image down below in our example of ubiquity nation notice over here on the left hand side, we're showing you a target protein here and these green circles with using them. Each represents a different ubiquity in peptide, each with 76 amino acid residues, and so we could go ahead and label these green use as ubiquitous in peptides. And so, of course, this arrow here represents the process of ubiquity nation, which we know is an 80 p dependent process. And so notice that it's utilizing a teepee in order to co violently attach the target protein here with these ubiquity in peptides. Now it turns out that these you Bickerton peptides are co violently attached to the target protein through the our group of ah lysine amino acid residue which is the amino acid residue that is most susceptible to ubiquity nation and so down below. What we can say is that these ubiquity and peptide here are going to be co violently attached to our target protein. Specifically through listens our group and so over here on the right hand side, we can get a better visualization of that idea and so notice that our target protein is represented by this red structure. Here. The squiggly line represents the remainder of our large red target protein. But notice that we're showing you that it's license our group which we know license. Our group ends with amino group at the end that is most susceptible to ubiquity nation. And so here we have the ubiquity in peptide and the car box. Late group of ubiquity and peptide can interact with license our group and through a mechanism here, uh, they are able to be co violently attached to each other. And so this blue bond here represents the co Vaillant attachment of the ubiquitous to the target protein through license our group. And so notice here that this bond right here is actually an AM I'd linkage since we have a car bottle group right here, and we the Carbonnel group is attached co violently to the nitrogen atoms. So this is an AM I'd linkage. Uh, and you might think that because these are proteins, uh, this eyes a protein and so is ubiquitous in because these are proteins and this is an AM I linkage. You might think that this is a peptide bond, but recall that peptide bonds are the ones that are in the backbone of the protein. Whereas because this amino group right here is not part of the backbone, it's actually part of license our group. Uh, this is actually not a peptide bond. Instead, sometimes it's referred to as an ISO peptide barred and is a peptide bond sometimes but other. Otherwise, you should be able to recognize this as an M. I'd linkage. Now, of course, What's important to note is that it's multiple ubiquitous, and peptides will actually linked together to form a chain of ubiquity in peptides on the target protein. And we kind of already saw that before. Over here in the image on the right, notice that we have a chain of ubiquity in peptides attached to our target protein. And so, through the same mechanism as up above we're able Thio, take another ubiquity and peptide and attach it co violently to the the target protein in this ubiquity molecules. So we form another bond right here, another Covalin bond. So we're linking these ubiquitous and peptides. And so in our next video, we're going to talk about exactly why it is that this ubiquity nation process is a form of regulation of protein activity. And so this here concludes our introduction to ubiquity nation, and I'll see you guys in our next video
2
concept
Ubiquitination
3m
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So what exactly is the purpose of ubiquity nation? Well, ubiquity nation actually targets protein, so it marks proteins for degradation by a complex known as a pro deism. And so what exactly are these Prodi ISMs? Well, Prodi zones are just large protein complexes themselves. That air specialized for Prodi elliptic activity. And so essentially, what we're saying is that these Prodi ISMs are specialized for breaking down large proteins into tiny, tiny peptide fragments and free amino acids. And so if we take a look at our image down below, noticed that the first part of this image here is exactly the same as it was in our last lesson video. And so we know that some proteins can be targeted for ubiquity nation, which is essentially taking these ubiquitous and peptides here and linking them into a chain to the target protein. And this is an ATP or an energy intensive process. And so here in this video, what we're learning is that ubiquity nation of ah protein actually targets that proteins for degradation by a large protein complex known as a pro deism. And so the Prodi is, um, is specialized for Prodi elliptic activity. So it's going to break down this, uh, targeted protein here into tiny, tiny peptide fragments. And so over here, what we have is the degraded protein. And so the ubiquity and peptides here can actually be recycled and reused to target another protein protein. And so, as the name ubiquity Nation suggests, this is a very ubiquitous process. So it occurs in pretty much every single eukaryotic organism from yeast all the way up to humans themselves. And so this ubiquity nation process is a process of post translational modifications, and so it's going to regulate enzymes activities. And so that's because ubiquitous nation is actually going to lead to the decrease in cellular protein concentration, since it marks proteins for degradation. And so therefore, ubiquity nation can actually decrease in enzymes activity or initial reaction velocity V not, and so that makes ubiquity nation a very ubiquitous form of, uh, enzymatic regulation. Now, ubiquitous nation is so ubiquitous that it's pretty much capable of regulating virtually every single cellular process in ourselves, which is amazing and shows why ubiquity nation is worth studying and understanding. And so this year concludes our lesson on ubiquity nation and how it targets proteins for degradation. And so we'll be able to apply the concepts that we've learned here and some practice problems moving forward. So I'll see you guys in our next video.
3
Problem
_________ involves covalent attachment of peptides leading to _________ of the target protein by ________.
A
Ubiquitination ; Activation ; Proteasome.
B
Glycosylation ; Degradation ; Ribosome.
C
Ubiquitination ; Degradation ; Proteome.
D
Ubiquitination ; Degradation ; Proteasome.
E
Acetylation ; Activation ; Proteasome.
4
Problem
Which of the following is true regarding protein ubiquitination?
A
Ubiquitin tagged proteins are usually degraded in the cell.
B
Ubiquitin is a ubiquitous, small nucleotide.
C
Covalent attachment of ubiquitin usually occurs via the R groups of methionine amino acid residues.
D
Ubiquitin links to the target protein only via hydrogen bonds.
E
Only a and c are true.
F
All of the above are true.
G
None of the above are true.
5
Problem
Ligation of a ubiquitin peptide’s ______________ charged carboxylate group to the R-group of a target protein’s ___________ residue forms a(n) _____________ bond.
A
Neutrally ; Histidine ; Hydrogen.
B
Negatively ; Leucine ; Isopeptide.
C
Positively ; Lysine ; Ionic.
D
Positively ; Lysine ; Disulfide.
E
Negatively; Lysine ; Hydrogen.
F
Negatively ; Lysine ; Isopeptide.