Write a short essay describing how an mRNA may be regulated in three different ways by specific cis-elements and RBPs.

Video transcript

Hi everyone. Welcome back. Let's look at our next question. The cytoplasmic polly a denigration element binding protein or C B. E. P. Is an R. B. P. RNA binding protein that recruits proteins to regulate gene expression. One of these proteins is called masking. How does maskin help the C B. E. P. And C. P in maintaining post transcription regulation in eukaryotic cells? Well, one thing we probably should just quickly identify here. Um Our question is how does mass can help the C. B. E. P. And C. P. Well the C. P. E. Is the cytoplasmic poly poly ventilation element. That's the segment of RNA that the cBP that binding protein binds to in this regulation. And as you can tell by the name of poly distillation. It has to do with regulation of the poly a tail shortening or lengthening it. So let's think about the rule of C B. E. P. And how it might interact with maskin. As we think about answering a question. So I'm just going to put up a little um description here. So CPB actually most commonly activates RNA translation but it can also ask act as a repressor. So activation over here on the left is by binding to that C. P. Site and elongating the poly a tail lengthening. The poly a tail at this stage actually increases the rate of translation but it can act as a repress er when it recruits maskin or something it recruits another protein called parn. The poly ventilation specific ribbon nucleus. Um So maskin binds to the cap binding protein. This blocks the interaction with another initiation factor blocks the cap binding proteins interaction and prevents initiation of translation. So that's mask in specific role in post transcription regulation. So when we look at our answer choices we see we have choices of choice A. It shortens the poly A tail. Choice be it digests the ribs. Um Choice. See it binds to the cap binding protein or choice D. And inserts a premature stop code on in the sequence. And we see from our description that our answers choice. See it binds to the cap binding protein. So let's see why our other answer choices are incorrect choice A. Says. It shortens the poly A tail. Well that's not masking that does that. Um We see another way that the CPV acts as a repressor is recruiting parn. Um that polly ventilation specific nucleus and that shortens the poly A tail which also reduces translation. We saw on the left side here that elongating the poly A tail turns up translation. So shortening it has the opposite effect. So shortening the poly A tail is done by the protein parn not maskin. So that's why that's not a correct answer. Choice B says it digests the ribbons. Um Well that's not the function of maskin ribosome is digested after the newly synthesized poly peptide is released. Um ribosomes if they need to be digested. That's done by the license times in their role of kind of cleaning up cellular trash. So that's why Choice B. Is not our correct answer. And finally, Choice D. And inserts a premature stop code on the sequence. Well, that's most commonly caused by nonsense mutations that introduced a mutation that mutate a coding a code on, that code for an amino acid into a stop code on. So that's not the role of masking and therefore not our answer choice. So again, um how does maskin help the c p e b, c b e P and C P and maintaining post transcription regulation? Choice C. It binds to the cap binding protein? See you in the next video.