RNA Splicing animation lecture - This video animation explains about the principles of RNA Splicing. It also explains the role of RNA Splicing. Watch this lecture to know more details about the spliceosome mediated RNA Splicing. • Splicing junctions are recognized only in the correct pairwise combinations.  Chemistry of RNA splicing: The splicing of pre- mRNA molecules occurs exclusively in the nucleus. They exon -intron junctions of mRNA show specific sequences that are highly conserved. Introns typically begin with GU dinucleotide sequence at the 5' splice site and an AG dinucleotide sequence at the 3' splice site. The splicing events occur in splicing complexes called spliceosomes. It consists of pre-mRNA bound to small nuclear ribonucleoprotein particles (SnRNPs). These are found only in the nucleus. Each SnRNP is abundant in nucleus and at least 10^5 copies per cell. They are rich in uridine residues-- named as U1, U2......U6.  The spliceosome machinery splicing is catalyzed by a spliceosome formed from the assembly of U1, U2, U5 and U4/U6 SnRNPs.  Splicing pathway • U1 SnRNP binds to the 5' splice junction of the intron. • U2 SnRNP binds to a sequence called the branch point sequence. • A U4/U6 SnRNP and a U5 SnRNP interact, and the combination binds to the U1 and U2 SnRNPs, causing the intron to loop, thereby bringing its two ends closer together. • U4 SnRNP dissociates, resulting in the formation of the active spliceosome. • The SnRNPs in the spliceosome cleave the intron from exon1 at the 5' splice junction, and the free 5' end of the intron is bonded to an A nucleotide in the branch point sequence, forming an RNA lariat structure, involves an unusual 2'-5' phosphodiester bond formed between the 2'-OH of the adenine nucleotide in the branch point sequence and the 5' phosphate of the guanine at the end of the intron. • Next the intron is excised by cleavage at the 3' splice junction and exon1 and 2 are ligated together. The snRNPs are released at this time. The process is repeated for each intron. Thank You for watching our videos from Biology Animation Videos channel. This channel is created to compile animated biology lectures and videos from different animation sources. None of these videos are created by us. we just organize them and place them in YouTube for your understanding so If you want to know details about these animation please see the credit section for knowing the original content developer and please convey privilege and gratitude to them. Thank You. Our website- https://www.biologyanimationvideos.weebly.com Thank you for watching mRNA Splicing Animation.

• published: 05 Dec 2017
• views: 14073