The regulation of mRNA decay relies heavily upon deadenylases and decapping enzymes. Explain how these classes of enzymes are critical to initiating mRNA decay.

Video transcript

Hi everyone, welcome back, let's look at our next problem. It says M RNA decay consists of the following mechanisms except so we're thinking about the process of M. R. N. A. D. K. How what mechanisms are involved in that remembering that we want to find the answer choice. That is not a mechanism of M. RNA decay. Notice however, that we have choice D. Here which is all of the above. So there's a potential that all three of A. B and C. Are mechanisms of M. R. N. A. D. K. So let's look through our answer choices here. Choice A says most M. RNA is under undergo decay by the DEA ventilation dependent pathway. Well this is correct um We're not going to say that it's not our answer since we do have that all of the above option, but I'm gonna market here as a correct statement, we recall that R. M. R. N. A. S. Have a three prime poly a tail and as you might guess by the name D. A desolation, is that shortening of the poly A tail? And this is the beginning of pretty much all M. RNA decay mechanisms. So let's look down at choice D. It says D. A ventilation leads to the removal of the poly A tail and that is correct. That is something that goes on in M RNA DNA decay mechanisms. So we're going to mark that as a mechanism They were onto choice. See the five prime cap is left intact. Well, here we go, this one is not part of M. R. M. RNA decay mechanisms because either um we have one of two major pathways that occur following that dehavilland ventilation. The first one involves de capping, so a removal of the five prime cap and then a five prime prime decay. So that would say the five prime cap is not left intact, it's D capped. Or if we have three prime to five prime decay since that cap is at the five prime end, it's not part of that overall mechanism, because it doesn't even come in until the very end. So either way, whether you go three prime to five prime or five prime three prime, um leaving the five prime cap intact is not part of the mechanism of RNA decay. So that's why that is not um part of this arm RNA decay mechanism and so therefore is our exception that we're looking for. So choice C. Is our correct answer and we now know that D all the above is not correct. And then so we can go ahead, eliminate and B since we know that we don't have all of the above as our answer. So again, M RNA decay consists of the following mechanisms except choice. See the five prime cap is left intact. See you in the next video