for National Geographic News
A newly developed bio-computer allows scientists to "program" molecules to carry out "commands" inside cells.
Such devices could one day allow humans to manipulate biological systems directly, said the California Institute of Technology's Christina Smolke, who co-authored the study, which will be published tomorrow in the journal Science.
Bio-computers might eventually serve as brains for producing biofuels from cells, for example, or to control "smart drugs" that medicate only under certain conditions.
For example, a smart drug could sample a cellular environment and trigger a self-destruct sequence if disease is detected, Smolke said.
(See a glossary of genetic terms.)
The new bio-computer consists of snippets of engineered RNA assembled inside a yeast cell.
RNA is a biological molecule similar to DNA, which encodes genetic information, such as how to make various proteins.
In engineering terms, the bio-computer's "inputs" are molecules floating around inside the cell. The "output" manifests as changes in protein production.
For example, an RNA computer may be able to bind with two different molecules. If both target molecules attach to it, they trigger the device to change shape.
The altered bio-computer is now the right shape to bind to DNA, where it can directly affect gene expression and ramp up or slow down the making of desired proteins.
Those proteins can affect the cell in various ways, such as killing it if it is cancerous.
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