What is alternative intron splicing?
Alternative splicing is the process of selecting different combinations of splice sites within a messenger RNA precursor (pre-mRNA) to produce variably spliced mRNAs. These multiple mRNAs can encode proteins that vary in their sequence and activity, and yet arise from a single gene.
Does alternative splicing remove introns?
In splicing, some sections of the RNA transcript (introns) are removed, and the remaining sections (exons) are stuck back together. Some genes can be alternatively spliced, leading to the production of different mature mRNA molecules from the same initial transcript.
What is an alternatively spliced exon?
Therefore, alternative splicing, a type of post-transcriptional modification, is the process by which exons or portions of exons or non-coding regions within a pre-mRNA transcript are differentially joined or skipped, resulting in multiple protein isoforms being encoded by a single gene.
What does alternative splicing result in?
Alternative splicing is a molecular mechanism that modifies pre-mRNA constructs prior to translation. This process can produce a diversity of mRNAs from a single gene by arranging coding sequences (exons) from recently spliced RNA transcripts into different combinations.
What happens to introns after splicing?
During the process of splicing, introns are removed from the pre-mRNA by the spliceosome and exons are spliced back together. If the introns are not removed, the RNA would be translated into a nonfunctional protein. Splicing occurs in the nucleus before the RNA migrates to the cytoplasm.
What is the main purpose of alternative splicing?
The overall function of alternative splicing is to increase the diversity of mRNAs expressed from the genome. Alternative splicing changes proteins encoded by mRNAs, which has profound functional effects.
How does alternate splicing work?
In alternative splicing, interactions between different proteins, the cell, and the environment can cause different segments of the original DNA to be omitted from the mRNA. When this happens, the alternate mRNA is translated into an entirely different protein.
What is the role of alternative splicing in evolution?
Alternative splicing enables organisms to produce the diversity of proteins necessary for multicellular life by using relatively few protein-coding genes. Although differences in splicing have been identified among divergent taxa, the shorter-term evolution of splicing is understudied.
What drives alternative splicing?
Splicing is regulated by trans-acting proteins (repressors and activators) and corresponding cis-acting regulatory sites (silencers and enhancers) on the pre-mRNA. Together, these elements form a “splicing code” that governs how splicing will occur under different cellular conditions.
What is the mechanism of alternative splicing?
What is alternative splicing and where is it found?
It is found in nearly all eukaryotic organisms that carry out standard nuclear pre-mRNA splicing, including animals, plants, and, in some cases, fungi. Alternative splicing is modulated by many proteins which interact with a large array of splicing enhancer and splicing suppressor sequences.
Can alternate splicing occur in mRNA translation?
This spliced mRNA is now ready to be translated into a protein. However, alternate splicing can also take place. While the entire mechanism is not well understood, it is known that certain chemical factors can stimulate the spliceosome to operate in different ways.
Can a spliceosome alternatively splice primary RNA?
See the examples section for specific examples. Below is a generalize chart showing the different ways a spliceosome can alternatively splice a primary RNA. There is another form of alternative splicing, known as trans splicing, in which exons from two different genes get assembled together by a spliceosome.
How many protein isoforms does alternative splicing produce?
From Wikipedia, the free encyclopedia Alternative splicing produces three protein isoforms. Alternative splicing, or alternative RNA splicing, or differential splicing, is a regulated process during gene expression that results in a single gene coding for multiple proteins.
