Types of Small Noncoding RNAs

Jason Amores Sumpter
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in this video, we're going to introduce two different types of small non coding RNA. Yes. And so again, there are two classes of RNA is that are involved in R N A. I or RNA interference. And so the first class is going to be the micro RNA days and the second class are going to be the small interfering RNA Zor for sure, the S I r n A s. And so both types of RNA, the micro R N s and the small interfering RNA s are going to bind to a target mRNA by complementary base pairing. And it's going to turn off expression of a gene through RNA interference. So both micro our knees and small interfering RNA is will turn off expression of a gene. And so what is the difference between the two? Well, the only difference between micro RNA s and S I. R N A s is the structure of their precursor form. And so micro RNA is have a single stranded precursor and s i r N s have a double stranded precursor and so we can take a look at this, uh, in our image down below. And so notice. In this example, we're showing you RNA interference by two types of small non coding. RNA is the micro RNA s and the S I R N s. And so, once again, over here on the far left, we have our miniature version of the map of our lesson. And, uh, notice that RNA interference is really taking place here with M RNA degradation, which is going to occur in the cytoplasm. But it also is going to block translation as well. And so it is a type of translational regulation as well Here and so over here on the left hand side noticed that we're focusing on the micro R N s and the micro RNA is are going to have a single stranded precursor. And so this is the precursor for the micro RNA. And then the micro RNA is going to complementary bind to the m r n a itself and it is going to block transcription. I'm sorry. It's going to block the next step, either mark the molecule for degradation or block the ribs, um, from binding and block translation. And so it is a way of turning off the gene Now, over here on the right hand side, we're focusing on the S I r n s the small interfering RNA s and they have a double stranded precursor. And so notice that up above, we're showing you a double stranded precursor molecule. And so ultimately, it will be converted into its single stranded s i r N A. And it's going to be very, very similar. Under both conditions, they both are going to be complementary, binding to the m r n a. And again it can either mark the M RNA for degradation or it can block the ribosome from translating. And so, in either case, it is going to be interfering with the RNA. It is a type of RNA interference and it will be turning off the genes. And so really, the main learning objective here is that the micro RNA s are going to have single stranded precursors, whereas the S R R N s are going to have double stranded precursors. But other than that, they're going to be very, very similar in their functions. And so this year concludes our introduction to the different types of small non coding RNA s 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.