Alternative Splicing

Alternative Splicing

Living cells, like programmers, increase their efficiency through repurposing code. Just as a programmer rearranges functional modules to create different outcomes, RNA transcripts can be rearranged to create different proteins. For RNA, exons are similar to program modules in that they often correspond to functional parts of proteins. Thus, in rearranging the exons, mRNA rearranges the functions of the protein product. In practical terms, this means that when raw RNA transcripts are spliced into more than one type of mRNA, they produce more than one functional protein product. This process is known as alternative splicing. Alternative transcripts may differ at the beginning or end of transcripts, or change which exons are used to create the final product. While alternatively spliced mRNAs appear in healthy cells, sequence variations that disrupt normal splicing are common in diseases like cancer.