What is the function of spliceosomes in gene expression?

The function of spliceosomes in gene expression is specifically to remove introns from pre-mRNA and splice exons together. In the process of gene expression, initially, the whole gene (including both coding sequences or exons and non-coding sequences or introns) is transcribed into pre-mRNA. Spliceosomes are complex molecular machines made up of small nuclear RNAs (snRNAs) and protein components that recognize the boundaries between introns and exons. They catalyze the removal of introns and facilitate the joining of exons, resulting in a mature mRNA transcript that can be translated into a protein. This step is crucial because only exons contain the information needed to code for proteins, and the presence of introns in the final mRNA would disrupt the coding sequence, leading to nonfunctional proteins. Thus, spliceosomes play a vital role in ensuring that the correct portions of the gene are expressed for protein synthesis.