RNA splicing is the process where introns are removed and exons are joined together to form mature mRNA. It occurs in the nucleus and involves two main types: self-splicing, where the intron splices itself, and spliceosome-mediated splicing, which uses small nuclear ribonucleoproteins (snRNPs) containing small nuclear RNAs (snRNAs) and proteins. The five major snRNPs involved in spliceosome-mediated splicing are U1, U2, U4, U5, and U6.

1. “RNA SPLICING”
Submitted by : Hira Naveed

2. RNA (Ribonucleic Acid):
• RNA is much more abundant than DNA
• There are several important differences between RNA and DNA.
• The pentose sugar in RNA is ribose, in DNA it’s deoxyribose.
• In RNA, uracil replaces the base thymine (U pairs with A).
• RNA is single stranded while DNA is double stranded.

4. SPLICING:
• The process of cutting the pre-mRNA to remove the introns and joining together of
the exons is called splicing.
• TAKES PLACE: “in the nucleus”.
• INTRONS: “non-coding sequences”.
• EXONS: “coding sequences”.

5. Types of splicing.
1.SELF SPLICING:
• Introns itself
2.SPLICOSOME MEDIATED SPLICING:
• SnRNp’s

6. Self splicing:
• Introns are able to excise itself precisely from the RNA precursor without the
involvement of any proteins.
• specified by the intron RNA itself.
• Doesn’t require snRNp’s.

8. SNRNP PARTICLES: SNRNA + PROTEINS
• Eukaryotic nuclei contain many discreet small RNA species called small nuclear
RNAs (snRNAs) are rich in the base uracil, which complex with specific proteins to
form snRNPs.
• The most abundant snRNP are involved in pre-mRNA splicing are :
• U1
• U2
• U4
• U5
• U6.