A biocomputer inside a living cell
Scientists from the California Institute of Technology have created biocomputers based on RNA, according to MIT Review (Computing with RNA). The work of scientists (Higher-Order Cellular Information Processing with Synthetic RNA Devices) is published in the journal Science.Biocomputers consist of three main components: sensors, transmitters and actuators. The first detect the presence of molecules of a certain type in the cell, the second transmit information about the detection, and the third start the production of a special protein.
Scientists used live yeast cells as a "working body". Functional elements were assembled inside them from fragments of various RNA molecules. Fragments of RNA aptamers played the role of sensors. The behavior of these molecules is similar to the behavior of antibodies. When a molecule of the substance they are tuned to is detected, the aptamers attach to it. The role of information transmitters was performed by "pieces" of RNA, which were activated after the detection of the necessary molecules by aptamers. The role of the executive elements was played by the so-called ribozymes - RNA molecules with a catalytic effect.
The researchers' computers had two types of sensors: one registered the presence of tetracycline molecules in the cell, and the other – theophylline molecules. Using the remaining components, the scientists managed to assemble the simplest logic devices inside the cell. Some reacted only to the simultaneous presence of both types of molecules (logical multiplication), others – to the presence of at least one of the two types (logical addition). The executive modules triggered the production of fluorescent protein in the cells.
According to scientists, the new discovery will allow programming biological processes. As an example, the researchers cite the possibility of creating "smart" drugs that will attack only malicious viruses without affecting other processes in cells.