mRNA Splicing

[ArtsyPetals]

i watched this vid about and hour and a half ago and was like wtf. Watched so more random vids on dna and rna, came back and was like i kinda get this sh*t now.

[acynosure]

It'll be more useful if they point out which one is U1, U2, U4, U5, and U6

[samiya630]

if you can also explain the lariat loop formation it'll be great i always tend to forget exactly what happens

[DDhannique]

Is GU and AG the only bases fond at the end of introns?

Does this mean the splice site is constant?

[samiya630]

@DDhannique these are actually the bases where splicing occurs there are many other AG and Gu sequences within the intron but the splicing occurs here

[soccerchic315]

so how does this make it possible to have 100,000 proteins with only 30,000 genes?

[MrDonMillie]

@soccerchic315 alternative splicing. different exon combinations will form different proteins from the same pre-mRNA

[whiterose855]

@soccerchic315 through the process of alternative splicing. a single primary transcript can be spliced into different mRNAs by the inclusion of different sets of exons.

[Irxoad]

Una figata assurda :O

[namemydoglola]

Youtube teaches me better than my 15k a semester top 40 school ever could.....how sad.

[monomnn]

What a great video!

[reck1ess77]

that was epic.

[nutnear]

thanks :))

[MrDeking10]

Im learning my science degree from youtube!!

[prinschelli91]

my final is tomorrow and i just started studying for bio. im such an idiot.

[watchingmymoments]

ohhhhhhh! UNIVERSITY DOES TRY TO MAKE IT HARDER TO UNDERSTAND, WHEN CLEARLY A VIDEO LIKE THIS IS CLEAR CONCISE AND EAY TO UNDERSTAND.. I AM SURE IT IS ALL A GAME OF 'POWER PLAYING' FOR MOST OF OUR LECTURERS,,,,,,,THEY ARE THERE FOR STATUS, NOT TEACHING...

WELL DONE TO THE MAKERS OF THIS VID, AND THEIR VIDS ON TRANSLATION AND TRANSCRIPTION.

[SiberianHuskyF1]

lovely video but a lot of it went over my head-i'm only at leaving cert level in dna and rna

[snm01]

How many of you just went "OHHHHHH" after watching this? i know i did.

[brunda13]

@snm01 I was more like "GU-AG!" :D

[Julianafanana]

Good video, but very general. Would appreciate the components of the splicosome being named.

[cstarvideo]

This is a great video! It would only be better if you could name the snRNPs as they attach to the mRNA. Also, one inaccuracy is that the video doesn't show U1 and U4 leaving the complex after the spliceosome is activated for the following transesterifications.

[cstarvideo]

This is a great video! It would only be better if you could name the snRNPs as they attach to the mRNA. Also, one inaccuracy is that the video doesn't show U1 and U4 leaving the complex after the spliceosome is activated for the following transesterifications.

[catskinner1002]

These are great videos, thanks.

[ninjasandeep]

Its a good video, but nothing has been told about the mechanism behind the cleavage.

[cacarito1990]

Thanks

[xxMakotosanxx]

Why do they teach this stuff to highschool freshmen? My teacher should at least get us a normal textook that's easy to understand like this video and not a college level one.

[zackboomer]

I use youtube videos along with textbook readings and I learn stuff so much easier since I am a visual learner. Yes there are pictures in the textbook, but seeing it in video form with a simple description makes reading the more complicated description in the text much easier. Thanks!

[92zkhan]

thanx

[greendayADDICT11]

i wish my teacher knew how to teach like you

[davidkeys100]

This is so comprehensive- nice job! 

[davidkeys100]

This is so comprehensive- nice job! 

[davidkeys100]

This is so comprehensive- nice job!

[GelandnaleG]

2:02

[tambulam]

grt...videos ...thanx virtual videos can u add some more videos on biotechnology........best videos in youtube

[xxN00Rxx]

thanxxx

[jesusfish305]

I kinda like the weird/creepy music, lol.

very very helpful, thanks.

[MegaMaitrayee]

this video helpd a lot......

[sannakhan1]

it helped..thanx

[SexyRaww]

so basically rna splicing is taking out the intron. Got it.

[njskiinglegend]

@SexyRaww Not just taking out the intron, but taking it out AND reattaching the exons together

[SexyRaww]

@njskiinglegend thanks lol but I took biology 2 semesters ago :P

[XSirApocalypseX]

The 5`-End (GU) of the Intron is fixing at the Branch Point (A).

Introns (INTervening RegiONS) are not coded Pieces of a RNA. At the Splicing, they will be depolymerised.

Exons (EXpressed regiONS) are the coded Pieces of the RNA, at the Splicing the Exon Parts will be fixed together.

prä-mRNA -> (Splicing) -> mature mRNA

There are also special Introns, that go in a enzymatic-conformation after Splicing.

Only Eukaryotes have Introns and Exons

[dtmd101]

The future of teaching biology is movies like this! great job on these!

[stealthtjah]

My book (The Cell; Alberts) says that eucarytoic mRNA can contain noncoding sequences. I thought that mRNA is formed after removal of the introns (noncoding sequences). So does mRNA only contain coding sequences? And is it possible that 1 mRNA molecule codes for more then 1 protein? Please help me, I am a little bit confused!

[faithlocket]

Is every time a little molecule "hits" a subunit an ATP hydrolysis???

[Hkoolg]

amazing

[ilikecandycane]

what is alternative slpicing?

[spicychickenwing31]

@ilikecandycane It is a process that produces alternate mature mRNA's, in which some exons are actually removed along with introns. This leads to a large diversity of gene products from a single sequence. Usually, you would have binding inhibitors or even promoters attach to an end of an exon (splicing sequence) to either inhibit or promote splicing at that end (affinity to spliceosome). Check out the regulation of alternative splicing in the determination of sex of drosophila for an example.

[MADhaTTer753]

Ribonuclease (RNase)...For ChickenWingChampoin's question.

[ChickenWingChampion]

how is the intron degraded? Proteosome?

[hypnonebula]

@ChickenWingChampion I guess not proteosome, since that's for protein... Most probably, RNAse enzyme is the one degrading the introns

[ChickenWingChampion]

cool. Thanks. YouTube is awesome!

[Spastb00n]

I am not so sure, but I read somewhere, that the poly-A-tail and the cap are there to prevent exonucleasis (english not first language)

from degrading it.

This implies, that exonucleasis is the type of enzime that usually degrades strands of RNA.

Don't quote me on this though.

[abhijit00004]

With the transcription of mRNA there is simultaneous modification in mRNA strand happens. Both ends of whole transcribed RNAs are capped, 5' end is capped with 7 methylguanosine and 3' prime is capped with poly A tail. Since the introns have neither of them and hence they are degraded by their unique 2'-5' (at junction of loop) bond. There are some other enzymes which recognize naked (without cap) 5'-3' ends of RNA molecule and degrade them.

[makbeus]

thanks!

[littlemissbossybee]

pff, the music is the best part

[roninanimelover]

This really helped me a lot in my medical studies! Thanks! =D

[betteronblondes]

the only downside to this video is the weird, creepy music in the beginning. Other than that, extremely helpful.

[hobbitsarecool]

agreed

[TeKNiQ50]

@betteronblondes LMAO! Excellent reply.

[chicwalk]

THIS IS INCREDIBLY USEFUL!!!!!!! THANK U!!! Sooo much better than my prof.

[MickBReedy]

i can sum up pre-mRNA processing simply: god doin' work. ;)

[Ganonz0rz]

they dont say a damn thing about EJC

[lonelyjew]

Hmmm... This isn't what I'm learning in my genetics class. We're being tuaght that 2'OH on the A site, with the help of splisomes that change the conformation of the mRNA, attacks the phosphodiester bond at the where the first exon and intron meet making the lariet. Next, again via conformation, the exposed 3'OH of the first exon attacks the phosphodiester bond at the remaining exon/intron connection. I guess I'll just go by what we learned in class.

[TiborZutron]

I think this was implied by this video, but they used the term "cleaved" as a general catch-all. You're right, the bonds aren't cleaved by enzymes, but by nucleophilic attack via conformations. L'chaim!

[raven1234]

I like how the ATP ---> ADP look in this animation.

[kvvful]

its very clear thanks a lot

[nkechi435]

ahhh... not specific at all, what about the U proteins!

[Forlo12345]

The U subunits ARE there. They make up the spliceosome. In fact, the U1 and U4 subunits are supposed to dissociate before the lariat is formed. Of course, they didn't mention that, BUT they did show the subunit corresponding to U1 dissociate from the mRNA.

[legogon81]

Это генетика???

[rehmsmeyer]

In Soviet Russia, exons splice YOU!

[harpoon67]

Totally just said that in a Russian accent and it was amazing.

[dadadioda]

isn't it that U4 and U1 are detached as U6 and U5 are attached to the complex? that's what I learned.....

[Forlo12345]

Yeah, that is what happens. And I don't know why people are getting thumbs down for pointing that out because it is true. I will likely get thumbs down too for saying that. In order for the lariat to be formed...U1 and U2 MUST leave the spliceosome.

[iep]

it was kinda helpful

[tc5arelove]

pretty cool video! illustration helps a lot in bio (:

[sappy490]

splicosome.. cool name it has

[pearpear89]

Perfect! the videos is very easy to understand. Thanks a lot.

[MsGrammarnazi]

VERY helpful..

thanks

[rstigerback]

just what i needed, thanx!!

[TheYoungistani]

nyc video bt u should label all the enzymes...its hard to understand

[marcorossi11]

Qui si capisce che il ripiegmento ad ansa è effettuato dalla snRNP-U1, ma in realtà è la U6 che lega da una parte la U2 e dall'altra la sequenza di splicing al 5', per poi catalizzare i tagli degli introni.ù

Cmq ottimo video, come tutti quelli dell' ndsu!!!

[TheYoungistani]

huf qunulali tui chee chee....cheeeeeeeeeeeeeee oolala omore macho myblo khokhar khota ....try to understand;)

[marcorossi11]

it is not a strange language, it's simply ITALIAN..you just have to translate it..it shouldn't be so hard, even for you!

[SeaspineEdu]

I'm looking for the 3' of the splice leader but can't identify the sequence. Any suggestions?

[demitry84]

in case some of you want extra details here's some:

1) A phosphodiester bond is formed between the 2' OH of branch site Adenin and the 5' end of the intron.

2) The free OH displaces the 3' end of the intron and another phosphodiester bond is formed between the OH and the 5' end of the following exon.

[tctk1]

thanks........ but a A phosphodiester bond is actually formed between the 4' OH and the lactase phosphofructokinase end of the ligase ester.  NT

[demitry84]

thanx alot for the video!!

exactly what i need :)

[KillaTequilla83]

nice thanks so much, im studying off your vids for my AP bio final haha

[Shrubbs]

Extremely helpful!

[WandsandMagic]

Is this what is known as alternative splicing?

[thegto2007]

what are

"A" branch site

Pyr-rich region

?

or what are they doing ?

[ndsuvirtualcell]

Both of those terms refer to the nucleic acids (or nucleotides) that make up a strand of mRNA. The "A" refers to adenosine, and "Pyr-rich" refers to an area with a large quantity of pyrimidines. They act as signals/locations for parts of the process.

[Johnak4715anos]

Your video description has an error: it says exons are removed and introns form the protein. It's the opposite.

[gzz104]

Listen to this again. It is accurate.

[Johnak4715anos]

It's the description that's wrong. The video is accurate.

[ndsuvirtualcell]

Thank you for catching that--it's fixed!

[dodopal]

realy good vedio it helped me to understand splicing for mulecular test...hope it will be ok

realy thanks and i agree that professors makes it so hard and complicated

[gothickid13]

i didnt gt Any of tht

[SevenHundredMillion]

Simply Brilliant

[medicineshogun]

Thanks

[kicktopo]

such an easy way to understand , i dont know why college proffs make it look so f hard?

[Karla02908]

so agree! we learnt this in our lecture today but i didnt understand any of it until watching this video :)

thanks for uploading!

[bnasdon]

@kicktopo HAHAHA that's exactly what i was thinking too before i even read your comment xD

[GraceOkello]

I know!

[exaltednoble]

Thank you for this and other videos. They are really very helpful. I read this stuff many times but could not understand clearly. But after viewing it here I got a clear understanding of the process.

[browneyes4539]

All of your videos are very helpful. Thank you so much! They are very clear as well.

[NETSEMRY]

what is the purpose for the splicing? Ridding the organism of decay or illness, repair?

[kittenkat88]

removing exons, the non-ciding parts.

[NETSEMRY]

ok this is new information for me and I havent researched this form of science yet, so bare with me the intron from what im reading is the sequence of dna that promotes bacteria or attacks it? the exon is the movement of the cell? Next question what is a good book to buy to get familar with this science that is easy to understand for a new commer to this information?

[kittenkat88]

I'm sorry, what I wrote there is actually wrong. It's not removing exons, it's selection for them. Introns are the non-coding parts. Extrons code for the production of proteins. Why don't you just try the wikipedia articles on introns, exons, transcription and translation?

[NETSEMRY]

yeah i did wikipedia already it was very vague. thanks for the information this is a very interesting topic i cant wait until more is known and explained about it all.

[Jorfapigo]

The DNA has this introns and exons to protect itself from mutations, it has not been clarified if these exons have other function at all (but i think they do)

The process cuts out the introns and leaves the exons in the right sequence for translation, codification, etc.

I hope you find this useful. DNA is such an amazing thing... from millions of years of evolution... AMAZING!

[NETSEMRY]

thank you very very much for that information it brings better light to this science for me. thank you.

[xCaptJackSparrow3x]

The Introns are non-coding parts and exons are coding. If the DNA was transcribed the way it is, you get an mRNA with introns and exons, if you translate this right away (mRNA -> Protein), then you would get a non-functional result.

Think of mRNA as a sentence:

5' [The](Circle)(Tree)[Dog](Fat)(­Lemon)[is](Pizza) [Yellow] 3'

Doesn't make too much sense if you read it like that. But Take out the (Introns) and combine the [Exons] and you get:

5'(The Dog is Yellow) 3'

A Functional mRNA Molecule

[xCaptJackSparrow3x]

5'(The Dog is Yellow) 3' should be

5'[The Dog is Yellow] 3'

in [Brackets] to represent the splicing (combining) of Exons, not introns. In case that caused any confusion.

[NETSEMRY]

ok the next question is a mutation something like (the tree is lemon yellow)? instead of (the dog is yellow)?

[xCaptJackSparrow3x]

Mutation is a whole topic itself, there are a bunch of diff. kinds of mutations, can be in the base pair arrangement itself (Point, silent, missense, and frameshift mutations) or dealing with the base pairs in regards to the chromosome (Duplication

[xCaptJackSparrow3x]

(whoops, hit post by accident)

So in regards to the chromosome (Duplication, Deletions, Inversions, and Translocations) Mutations can be Balanced or Unbalanced (Depending on overall addition/subtraction of base pairs) and either stable to unstable (Can be passed on to offspring or can't be passed on).

Mutations can occur in a variety of different ways, one of the most common ways (i think) is when a cell undergoes nondisjuction (fails to seperate completely) during cell division.

[NETSEMRY]

some of that mutation is what science calls junk dna correct?

or what science would call evolution but the fact is that its like having a lot of stuff locked in a closet and your able to get a key take what you want out of the closet for an appropriate time.

[xCaptJackSparrow3x]

Well a quick review of DNA. DNA is made up of smaller segments called Genes. These Genes hold the code that tell the cell what to make (Such as different proteins).

The Genes are made up of even smaller segments called Codons. Human DNA is made up of 4 base pairs abbreviated by the letters G,C,A,T. Each codon is made up of 3 of these base pairs, they can be in any order and can be repeated. The order of these base pairs tells the cell which parts to attach together and what to make.

[NETSEMRY]

is it only or always a trinity combination? What would happen if all four G,A,C,T COMBINED? what would be the result?

[xCaptJackSparrow3x]

All the bases G,C,A,T are all combined onto one strand in different orders, but they can only be "read" three at a time, in triplet code. The amino acids on tRNA molecules are attached together to form a polypeptide according to the sequence of base pair on the mRNA read 3 at a time.

Each group of three base pairs corresponds to a specific tRNA and amino acid, which are all peptide linked together to make a protein.

Search and watch a video on DNA Translation, that should explain it.

[NETSEMRY]

this science has to be your field of work am i correct xcaptjacksparrow3x? What is it you do?

[xCaptJackSparrow3x]

This is not my work, I am a Medical Student and this material is really basic and is usually learned in any college-level Biology 1 or 2 class. I say it's basic because this material can go into so much more detail, but you need to have a solid understanding of this type of material in order to understand the more advanced concepts.

[NETSEMRY]

Ill buy that for a dollar!~

basic stuff, im actually a high school drop out and i just read tid bits here and there,College wouldnt accept me im not that smart for this shit, so i study stuff on my own....hope you find a wonderful career in this stuff if its your choosing. Why do you choose the name xcaptjacksparrow3X?

[0whyhaveaname0]

Junk DNA actually is not referred to as "Junk DNA" its now noncoding DNA. Scientists have determined that it actually does something but they are unsure what it is. It is now noncoding DNA because it is not responsible for producing polypeptides(proteins and enzymes)

[NETSEMRY]

then how can scientist say its noncoding DNA when they dont actually know what it is? I mean to name something you have to know its function, Maybe science should call it we dont know what the hell it is.

From my reading on this subject i learned that the so called DNA or closet DNA gets turned on when its supose to.

[NETSEMRY]

Now in this time in history it doesnt turn on, that lets me know the supreme creator knows when to work or turn his creations on at the proper time. Just because science doesnt know its true function doesnt mean its noncoded.

[Mattprole]

Without evidence to the contrary, I would presume they are mostly right. They call it noncoding DNA because that seems to be the only definitive function that can be applied to it; it dosen't code like the exon portions do, so they name it appropriately.

[nickism100]

i cried

that was beautiful *snif*

[pauliwauli2]

I actually find that quite disrespectful, Nic Cotton. Or whatever you name is.

[Generalxagent]

Why is this disrespectful? Nick is marveling at the complexity of mRNA splicing! Oh, and it's way more complicated then what's shown here.

[gloriakenny]

are u guys kiddin me right? i gotta read 120 pages by tomorrow

[tawfikakkad]

i hate dry text books

[LeeDiddy990]

correct me if I am wrong isn't it true that the phosphorlyation of carboxyl tail is requried before the processing of mRNA can occur.

[SpydermanGST]

I don't think so. Are you thinking of the sigma factor?

The only other thing that I can think of that you are talking about is the catalytic component of RNAP that is responsible for elongation of the transcript. That catalyzes the linkage of rNTP's with phosphodiester bond.

If that didn't clear it up, just let me know.

[roarixer]

The video was good for general reference, but it fails to discuss details and the activation of spliceosome and other important proteins such as TFIIH. Also, it did not mention the importance of phosphorylation.

[roarixer]

nvm...this was intended for the transcription video

[LeeDiddy990]

Thanks so much for this animation. it explains the concepts in a straight forward method much better than my professor explained it.

[jopiaddict]

This video rocks :)

[biodudios]

Just amazing!!

[Lansvacer]

that is so beautiful.

[mrkk123]

This makes things finally clear! Why can't my porfessor show a short animation like this one instead of telling endless stories about this process?

Thank you very much!!

[KMLDA]

Thanks i got my final in molecualr biology in a couple of weeks and that cleared things up!

Yehaaa!!! 11 exmas in 8 days..

[masteryan]

ELEVEN?!?!

[KMLDA]

yup, had 7 last week, four to go. crazy.. never, ever to university in belgium! thats my advice

[masteryan]

Wow that;s gotta suck.

I got one tomorrow, then tues, then wed, then thurs. FOUR IN A ROW.

But id prefer that, than have 11. haha

[whateverdude789]

u think that's bad guys? in my country its usually about 7-8 papers in about 2 freakin months!!!! trust me having exams that drag for such a long time aint even funny!!!

[yvikas70]

I learned more from that 2 minute video, than the 100 min lecture that my professor gave.

[TasteySpread]

Lol, what kept, hitting the complexes and bouncing off?

[golfirgurl]

that is ATP. it is energy used by these molecules for the reaction

[sepikpes]

really good explanation, thanks, i get it now :)

[JAJAJAFT]

wonderful!!!