Which snRNPs are involved in the splicing process?

The involvement of specific small nuclear ribonucleoproteins (snRNPs) in the splicing process is fundamentally important for the accurate processing of pre-mRNA. The correct answer encompasses U1, U2, U4, U5, and U6 snRNPs, which play vital roles in RNA splicing.

U1 snRNP is crucial for recognizing the 5' splice site of the intron. It binds to the pre-mRNA and helps initiate the splicing process. U2 snRNP binds to the branch point sequence within the intron, which is essential for subsequent steps in splicing.

U4 and U6 snRNPs function in a complex together, where U4 initially masks U6 to prevent premature interaction with the pre-mRNA. Upon activation of the spliceosome, U4 is released, allowing U6 to interact with U2 and facilitate the formation of the catalytic site of the spliceosome. U5 snRNP is important for holding the exons together so that they can be ligated after intron removal.

The combination of these snRNPs forms the spliceosome, the molecular machine responsible for excising introns from pre-mRNA and joining exons together