snRNA processing

Definition

Target type: biologicalprocess

Any process involved in the conversion of a primary small nuclear RNA (snRNA) transcript into a mature snRNA molecule. The primary function of snRNAs is processing pre-messenger RNA in the nucleus. They have also been shown to aid in the regulation of transcription factors (7SK RNA) or RNA polymerase II (B2 RNA), and maintaining the telomeres. [PMID:15196465, PMID:31815536]

snRNA processing is a complex and essential biological process that involves the maturation of small nuclear RNAs (snRNAs), crucial components of the spliceosome, a molecular machine responsible for removing introns from pre-messenger RNA (pre-mRNA) during gene expression. This intricate process can be summarized as follows:

1. **Transcription:** snRNA genes are transcribed by RNA polymerase II, producing primary transcripts known as pre-snRNAs. These transcripts contain exons and introns, similar to pre-mRNA.
2. **5' capping:** The 5' end of the pre-snRNA is capped with a 7-methylguanosine (m7G) cap, which protects the RNA from degradation and assists in its recognition by the spliceosome.
3. **3' end processing:** The 3' end of the pre-snRNA is processed by a complex of enzymes that cleave the transcript at a specific site and add a 3' hydroxyl group.
4. **Splicing:** Pre-snRNAs undergo a unique type of splicing called "autosplicing" where they splice themselves. This process removes introns and joins exons, forming mature snRNAs.
5. **Modification:** Mature snRNAs undergo various modifications, including methylation and pseudouridylation, which are crucial for their proper function and stability. These modifications alter the structure and properties of the snRNAs, contributing to their specific interactions with other spliceosome components.
6. **Assembly:** Mature snRNAs associate with specific proteins to form snRNPs (small nuclear ribonucleoprotein particles), also known as "snurps." Each snRNP contains a specific snRNA and a set of proteins.
7. **Spliceosome formation:** Different snRNPs assemble into a larger complex, the spliceosome, which catalyzes the removal of introns from pre-mRNA.

The proper processing of snRNAs is crucial for accurate gene expression. Errors in snRNA processing can lead to defective splicing, resulting in the production of non-functional proteins and various diseases. '
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Proteins (1)

Compounds (15)