mRNASpleißreaktion

The mRNASpleißreaktion, often referred to as mRNA splicing in English, is a crucial post-transcriptional modification process in eukaryotic cells. It involves the removal of non-coding sequences, known as introns, from a precursor messenger RNA (pre-mRNA) molecule and the joining of the coding sequences, called exons, together. This process is essential for the production of functional mRNA that can be translated into proteins.

The spliceosome, a large and dynamic molecular machine composed of small nuclear ribonucleoproteins (snRNPs) and numerous additional proteins, catalyzes the mRNASpleißreaktion. The process begins with the recognition of specific sequences at the boundaries of introns and exons, known as splice sites. These sites are typically a GU sequence at the 5' end of the intron and an AG sequence at the 3' end, with a branch point adenosine within the intron.

Through a series of coordinated RNA-protein interactions and conformational changes within the spliceosome, the intron is excised in a lariat structure, and the flanking exons are ligated. Alternative splicing, a variation of this process, allows a single gene to produce multiple protein isoforms by including or excluding certain exons. This significantly expands the protein-coding potential of the genome and contributes to cellular and organismal complexity. Errors in mRNASpleißreaktion can lead to the production of non-functional proteins and are associated with various diseases.