A new study has revealed cellular activity, hinting at the fact that recycling is in our DNA. Check out more details about the interesting spliceosomes.
Cellular activity shows recycling present in our DNA
Spliceosomes are microscopic machines that can put back together the broken data in our genes by removing sequences called introns so that our messenger RNAs can make the correct proteins that are needed by cells.
Introns are probably one of the genome’s biggest mysteries; they are DNA sequences that interrupt the sensible protein-coding info in our genes, and have to be spliced out.
The human genome contains a large number of introns, which are non-coding regions in the DNA. Typically, there are around 7 or 8 introns per gene.
These introns are removed by a specialized RNA protein complex known as the “spliceosome”. The spliceosome cuts out the introns and splices together the remaining coding sequences, called exons.
However, we do not yet know how this system of broken genes and the spliceosome evolved in our genomes.
Throughout his lengthy career, distinguished professor of Molecular, Cellular, and Developmental Biology at UC Santa Cruz, Manny Ares, has dedicated himself to studying RNA splicing.
“I’m all about the spliceosome,” Ares said. “I just want to know everything the spliceosome does—even if I don’t know why it is doing it.”
In a recent publication in the journal “Genes and Development,” Ares has made a surprising discovery about the spliceosome that could provide us with more information about how different species have evolved and how cells have adapted to the issue of introns.
The authors have found that even after the spliceosome has completed splicing the mRNA, it remains active and can participate in further reactions with the extracted introns.
This finding indicates that spliceosomes may have the ability to reinsert an intron into the genome in another location, which was not previously believed to be possible.
According to Phys.org, this characteristic is commonly found in “Group II introns,” which are distant relatives of the spliceosome that exist primarily in bacteria.
The spliceosome and Group II introns are believed to have evolved from a common ancestor that was responsible for spreading introns throughout the genome.
While Group II introns can splice themselves out of RNA and then return to DNA directly, the “spliceosomal introns” found in most higher-level organisms require the spliceosome for splicing. These introns were not thought to be reinserted back into DNA.
It is unlikely that the spliceosome can reinsert introns into the human genome because human spliceosomes are in high demand and do not have much time to spend with removed introns.
However, in other organisms where the spliceosome is not as busy, the reinsertion of introns may occur more frequently.