Crop Biotech Update

Cells May Stray from 'Central Dogma'

May 20, 2011

Scientist Vivian Cheung at the University of Pennsylvania, Philadelphia and team discovered that the ‘central dogma' of molecular biology, stated as "the sequence of bases encoded in DNA determines the sequence of amino acids that makes up the corresponding proteins", could be more complicated than perceived. The scientists reported that "they have found more than 10,000 locations where the base (A, C, G, or U) in a cell's RNA messages is not the ones expected from the DNA sequences used to make the RNA read-out." When the mismatched RNAs were translated into proteins, the proteins reflected the "incorrect" RNA sequences, rather than that of the underlying DNA.

It has been known that some cells ‘edit' RNA after it has been made to produce a new coding sequence, but the new study implies that such editing happens much more often in human cells than previously perceived. Once the findings of the study are further confirmed by other researchers, it could change the understanding of the cell and the way the scientists study genetic contribution to disease.

Wistar Institute scientist Kazuko Nishikura, who is not part of the research team, says she was skeptical at first, because some of the base changes could not be explained by previously identified mechanisms. But the scientist was convinced after seeing Cheung's data. "It's really exciting, because this study reports a different variety of RNA editing that is much more widespread than existing mechanisms," said Nishikura.

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