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How is it possible for a single gene to code for two different proteins in eukaryotes?
Gene splicing is a post-transcriptional modification in which a single gene can code for multiple proteins. Gene Splicing is done in eukaryotes, prior to mRNA translation, by the differential inclusion or exclusion of regions of pre-mRNA. Gene splicing is an important source of protein diversity.
How can one eukaryotic gene lead to one transcript but multiple different proteins?
How do they lead to the production of multiple proteins from a single gene? Alternative processing of pre-mRNA can take the form of either alternative splicing of pre-mRNA introns or the alternative cleavage of 3′ cleavage sites in a pre-mRNA molecule containing two or more cleavage sites for polyadenylation.
Can the same gene produce different proteins?
A single gene can produce multiple protein sequences, depending on which exons are included in the mRNA transcript, which carries instructions to the cell’s protein-building machinery. Two different forms of the same protein, known as isoforms, can have different, even completely opposite functions.
Can multiple proteins be made from one gene in prokaryotes?
The intracellular level of a bacterial protein can quickly be amplified by multiple transcription and translation events occurring concurrently on the same DNA template. Prokaryotic transcription often covers more than one gene and produces polycistronic mRNAs that specify more than one protein.
How does one gene produce many proteins?
What does this mean? It means that the old paradigm that one gene makes one protein is clearly in need of revision. Through mechanisms that include “alternative splicing,” one gene can direct the synthesis of many proteins.
How can the expression of a single gene lead to the production of different proteins?
This process is known as splicing. RNA splicing involves the removal or “splicing out” of certain sequences in the mRNA, referred to as intervening sequences, or introns. Splicing different combinations of exon together can lead to the production of a variety of different proteins being produced from a single gene.
How do eukaryotes make protein?
Protein is a large molecule made from chains of amino acids, which are the subunits of protein molecules. Eukaryotes produce these proteins through a process called protein synthesis. Transcription is the process of creating mRNA from DNA, and translation is when ribosomes read the mRNA and synthesize a protein.
How does the protein process differ in prokaryotes and eukaryotes?
In eukaryotes, protein synthesis occurs in the cytoplasm. In prokaryotes, protein synthesis begins even before the transcription of mRNA molecule is completed. Therefore mRNA processing is not required. The primary mRNA transcript in eukaryotes undergoes processing and splicing to change into a functional mRNA.
Does a gene code for only one protein?
For a long time, one thing seemed fairly solid in biologists’ minds: Each gene in the genome made one protein. The gene’s code was the recipe for one molecule that would go forth into the cell and do the work that needed doing, whether that was generating energy, disposing of waste, or any other necessary task.
Where does a gene go to make a protein?
In brief, a gene is actually a recipe that the cell uses to make a particular protein. Since most of a cell’s DNA is in the nucleus, the “recipe” stored in that gene must leave the cell’s nucleus in order to be turned into a protein.
Where are proteins made in the eukaryotic cell?
To do that, the “recipe” is copied by a molecule called messenger RNA (mRNA). The mRNA then takes the copied “recipe” out of the nucleus to the ribosome, which is where proteins are made. In eukaryotic cells (the kinds of cells found in plants and animals), however, something very interesting happens before the mRNA leaves the nucleus.
How are genes expressed and regulated in eukaryotes?
The set of genes expressed in a cell determines the set of proteins and functional RNAs it contains, giving it its unique properties. In eukaryotes like humans, gene expression involves many steps, and gene regulation can occur at any of these steps. However, many genes are regulated primarily at the level of transcription.
Why are two different types of proteins produced by the same gene?
A single gene can produce multiple protein sequences, depending on which exons are included in the mRNA transcript, which carries instructions to the cell’s protein-building machinery. Two different forms of the same protein, known as isoforms, can have different, even completely opposite functions.