Eukaryotic Post-Translational Regulation

in this video, we're going to begin our lesson on eukaryotic post translational regulation, and so eukaryotes can regulate expression at the post translational level. Bye. Controlling the activity of the expressed protein. And so recall from our previous lesson videos that post translational modifications can be abbreviated as P. T. M's. And really, they are defined as Covalin modifications to proteins after translation takes place, and that is what the post route here is referring to. Post is referring to after now these post translational modifications or P T. M s. They can either activate or inactivate a protein, depending on the specific protein in the specific scenario, or they can actually tag the protein or mark. The protein for degradation by Proteus is, and so Proteus is are specific enzymes that are going to degrade proteins by breaking polyp peptide bonds, the bonds that link amino acids together. And so by breaking and degrading, uh, by degrading proteins. By breaking Polly peptide bonds, they're capable of making single amino acids. And so if we take a look at our image down below, we can get a better understanding of these post translational modifications, and so protein activity can be controlled by post translational modifications or the degradation by Proteus is. And so taking a look at our little mini map over here, which will notice, is post translational protein modifications occurs in the cytoplasm of the cell and so up above. What we're showing you is the M R N a. Here that's going to be translated into a protein. But in many cases, proteins that are initially translated can be inactive proteins. And so the post translational modification here includes this modification tag basically co violently modifying the protein to create an active protein. And so this is a form of turning on gene expression to ensure that there is an active protein product. And again, this is through post translational modification, a modification that occurs after translation has occurred. Now again, post translational modifications can also inactivate a protein as well, so it's also a form of turning off a gene Now down below. What we're showing you is again an M RNA being translated into a protein, Uh, and this time there is again a modification, all tag being added to the protein. But this time this tag is actually marking the protein for degradation by this Proteas enzyme, and this protease enzyme in blue is going to perform protein degradation to break up that protein into individual amino acids. And so, of course, if we are degrading the protein, then that is a form of turning off the gene. It's a form of regulation. And so, uh, what you can see here is that through post translational modifications, proteins can be turned on and or proteins can be turned off, depending on the specific scenario. And so this year concludes our brief introduction to Eukaryotic post translational regulation, and we'll be able to get some practice applying these concepts as we move forward in our course, so I'll see you all in our next video.

Protein degradation is one strategy to control gene expression and is considered ______.

• A. Transcriptional control.
• B. Post-transcriptional control.
• C. Translation initiation control.
• D. Post-translational control.
• E. Chromatin remodeling.

Post-translational modifications of proteins can affect which of the following?

• A. Protein function.
• B. Protein location within the cell.
• C. Protein activation or inactivation.
• D. Protein degradation.
• E. All of the above.

in this video, we're going to talk about protein ubiquitous nation. And so you corrodes need a way to remove or degrade proteins in a cell that are no longer needed. And so recall from our previous lesson videos that cells can utilize post translational modifications or P T. M s to tag specific proteins in a cell to be degraded by cellular. Proteus is these enzymes that degrade proteins. Now, in terms of ubiquity nation, you Bic Witten is actually a small peptide, a small fragment of protein that is going to be used by eukaryotic cells to mark other proteins for degradation. And so we'll be able to see this down below in our image. Now ubiquitous in Ligue Ace is an enzyme, a cellular enzyme that is going to add, uh, it's going to add the ubiquitous in peptide to target the protein for degradation. And so let's take a look at our image down below to get a better understanding of this. Uh, and in this example, we're looking at how ubiquitous ladies can add a ubiquitous peptide to misfolded or nonfunctioning proteins in order to get rid of them and remove them. And so, once again. This is a type of post translational modification that occurs in the cytoplasm and protein ubiquity nation. Basically, what you can see in this image is that the M RNA strain is going to be translated into a protein, perhaps an inactive or misfolded nonfunctioning protein. And so what can happen is this enzyme ubiquitous. Only gays can take this ubiquitous in molecule. This is ubiquitous in tag and take the ubiquitous tag and transfer it over to the tagged protein. So now we have a tag protein, and this tag protein has been tagged for degradation by the Proteas enzyme over here. And so the protease enzyme combined to the tagged protein and that is ultimately going to lead to protein degradation. And that will remove the protein that is no longer needed. That is non functioning or that is misfolded. And so this is a way of regulating gene expression as well, getting rid of proteins that are no longer needed. And so this year concludes our brief introduction to Protein Ubiquity Nation, and we'll be able to get some practice applying these concepts as we move forward in our course. So I'll see you all in our next video

A hormone signal reaches a cell and causes the cell to produce a large quantity of Protein X. After some time, the hormone signal disappears and the cell no longer needs a large quantity of Protein X. How will the cell remove the excess protein?

• A. The repressor protein for the Protein X gene will stop the transcription of the gene.
• B. The excess Protein X will be tagged with ubiquitin proteins and degraded over time.
• C. The Protein X mRNA will be bound by a microRNA blocking its translation.
• D. Over time the excess Protein X will diffuse out of the cell.