Spliceosome (pre-mRNA splicing machinery)

The **pre-mRNA splicing machinery** (commonly called the **spliceosome**) is a large and highly dynamic ribonucleoprotein complex responsible for catalyzing the removal of introns from nuclear pre-mRNA transcripts in eukaryotic cells. The spliceosome comprises five small nuclear RNAs (snRNAs: U1, U2, U4, U5, and U6) and approximately 150–170 associated protein factors in humans. These components assemble stepwise on pre-mRNA to recognize exon–intron boundaries and catalyze two sequential transesterification reactions, excising introns and ligating exons to generate mature mRNA. The splicing machinery regulates alternative splicing, influencing gene expression and protein diversity. Disruption or modulation of spliceosome function has therapeutic relevance in diseases like cancer, where alternative splicing is frequently dysregulated[1][4][6]. Drugs that target components of the splicing machinery can alter splicing choices or induce cell death, but these interventions risk toxicity due to the essential nature of splicing in normal cells. Specific mutations in splicing factors (for example, SF3B1, U2AF1) are found in several cancers and can serve as biomarkers or drug targets. **Note:** - The CDC5 family of Myb-related proteins are required for pre-mRNA splicing and are associated with the spliceosome, based on protein–protein interactions and colocalization studies, but they are specific components and not synonymous with the entire splicing machinery[3]. - If querying specifically for "MYB pre-mRNA," this is merely the precursor transcript for the MYB gene and not in itself a therapeutic target. - The most precise molecular target based on the query is the spliceosome or splicing machinery, not "MYB pre-mRNA / Splicing Machinery" as a combined entity. To summarize: "MYB pre-mRNA / Splicing Machinery" is not a canonical, singular molecular target. "Spliceosome (pre-mRNA splicing machinery)" is the correct entity, and the query as written is **incorrect** or at least imprecise. The information above provides everything needed for structured indexing according to your schema[1][3][4][6].

Other names

pre-mRNA splicing machineryspliceosomesplicing complex

Inhibition of spliceosome assembly or function Modulation of alternative splicing patterns