A team of scientists in the University of Seville, Spain, have recently uncovered that the closeness of the genes in eukaryotic cells to the nuclear pores, located in the nuclear membrane, helps in keeping the togetherness of the genome intact. This is because the lodging of DNA in the pore in the process of transcription prevents building of DNA-RNA hybrids that cause breaks in DNA and genome instability. This in turn can lead to cancer and neurodegenerative diseases.
For more than a decade, the physical proximity and lodging of the genes to the nuclear pores in the process of transcription, has been known. It enables carrying the nascent RNA out of the nucleus. In the particular research conducted by the team of scientists, it has been noticed that DNA lodged in the nucleus interior and expunged from the nuclear pore, results in the likelihood of DNA-RNA hybrids formation. Hence, lodging of DNA in the pore helps in keeping the integrity of the genome intact by thwarting formation of such structures.
Scientists Carry Out Experiment in Replica Eukaryotic Organism
The research was conducted on a replica of eukaryotic organism, the yeast species called Saccharomyces. A genetic count of new genes that stall formation of DNA-RNA hybrids was made in it. In one cluster of mutations of genes that encode proteins, the scientists found the nuclear parts of the macrocomplex, Mlp1 and Mlp2, which constitute the nuclear pores, was intact in every eukaryotes. The molecular analysis of the null mutations in these genes showed DNA-RNA hybrids had formed. When the DNA in these mutations was reinstated to the nuclear pore via an artificial anchoring system which has been genetically engineered, however, the hybrids were suppressed.