Biomolecular Control Systems

摘要

Humans have been influencing the DNA of plants and animals for thousands of years through selective breeding. Yet it is only over the last three decades or so that we have gained the ability to manipulate the DNA itself and directly alter its sequences through the modern tools of genetic engineering. This has revolutionized biotechnology and ushered in the era of synthetic biology. It has also made it conceivable for the first time to engineer into living cells genetic feedback control systems that automatically monitor and steer the cell's dynamic behavior. To realize the huge promise of such systems, new theory and methodologies are needed for designing controllers that function in the special and challenging environment of the cell. We refer to the resulting technology as Cybergenetics-a modern realization of Norbert Wiener's Cybernetics vision. Here I will present our theoretical framework for the design and synthesis of cybergenetic systems and discuss the main challenges in their implementation. I will then introduce the first designer gene network that attains integral feedback in a living cell and will demonstrate its tunability and disturbance rejection properties. A growth control application shows the inherent capacity of this genetic control system to deliver robustness and highlights its potential use as a universal controller for regulation of biological variables in arbitrary networks . I will end by exploring the potential impact of Cybergenetics in industrial biotechnology and medical therapy.