RNA Degradation
mRNA Digestion
The translational activity of active genes may be regulated by controlling the degradation of mRNA transcripts
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In human cells, mRNA may persist for time periods from minutes up to days, before being broken down
As mRNA provides the instructions required by the ribosomes for protein assembly, the longevity of the transcripts will determine the expression levels of a gene
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The longer a transcript lasts before degradation, the more protein will be produced (via translation)
The mRNA transcripts are broken down by nucleases to form single nucleotides that can be recycled by the cell
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The degradation of mRNA transcripts will alter the transcriptome within a cell at any particular point of time
Nuclease Activity
Protein Digestion
Post-translation, gene expression patterns can also be regulated by controlling the degradation of the proteins
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Proteins can be broken down by individual enzymes (proteases) or protein complexes called proteasomes
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Proteins targeted for degradation by the proteasome are first tagged by ubiquitin (via ubiquitination)
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The degradation of proteins will alter the proteome within a cell at any particular point of time
Proteasome Activity