Alternative Splicing: One Gene, Many Proteins
Definition
Alternative splicing
Alternative splicing is a process that enables a single gene to produce multiple protein variants.
- During transcription, a primary RNA transcript is created, containing both exons (coding regions) and introns (non-coding regions).
- Before translation, introns are removed and exons are spliced together to form mature mRNA.
- In alternative splicing, different combinations of exons are joined, creating multiple versions of mature mRNA from the same primary transcript.
- Each mRNA variant is translated into a different polypeptide (protein variant).
This is like swapping ingredients or changing steps, to produce multiple dishes from a single recipe.
How Alternative Splicing Works
- Primary transcript formation: Transcription produces a primary RNA transcript containing both exons and introns.
- Intron removal: Introns are removed by a complex called the spliceosome.
- Exon selection: The spliceosome joins selected exons in different combinations.
- Mature mRNA production: Each combination of exons produces a different mature mRNA.
- Translation: Each mature mRNA is translated into a different polypeptide.
Why Alternative Splicing Is Important
- Protein Diversity: It allows a single gene to produce multiple proteins, increasing the complexity of the proteome without expanding the genome.
- Functional Specialization: Proteins produced through alternative splicing can have different roles, enabling cells to adapt to various conditions.
- Efficiency: Instead of duplicating genes, organisms use alternative splicing to maximize genetic information.
How does the ability to produce multiple proteins from a single gene challenge the traditional "one gene, one protein" concept? What does this reveal about the complexity of genetic regulation?
Self review- Why is alternative splicing important for protein diversity?
- How does the spliceosome determine which exons to include?
- What are the potential consequences of errors in splicing?
