Self-assembling and self-organizing systems are the Holy Grails of nanotechnology, but nature has been producing such systems for millions of years. A team of scientists has taken a unique look at how thousands of bacterial membrane proteins are able to assemble into clusters that direct cell movement to select chemicals in their environment. Their results provide valuable insight into how complex periodic patterns in biological systems can be generated and repaired.
Researchers with the Lawrence Berkeley National Laboratory (Berkeley Lab), the University of California (UC) Berkeley, the Howard Hughes Medical Institute, and Princeton University, used an ultrahigh-precision visible light microscopy technique called PALM for Photo-Activated Localization Microscopy to show that the chemotaxis network of signaling proteins in E.coli bacteria is able to spontaneously form from clusters of proteins without being actively distributed or attached to specific locations in cells. This simple organizational mechanism - dubbed "stochastic self-assembly" is related to the self-organizing patterns first described in 1952 by the British computer scientist Alan Turing.
"It is not widely appreciated that complex periodic patterns can spontaneously emerge from simple mechanisms, but that is probably what is happening here," said Jan Liphardt, the biophysicist who led this research.
Liphardt holds a joint appointment with Berkeley Lab's Physical Biosciences Division and UC Berkeley's Physics Department. He is the principal author of a paper now available on-line in the Public Library of Science entitled: "Self-Organization of the Escherichia coli Chemotaxis Network Imaged with Super-Resolution Light Microscopy." Co-authoring the paper with Liphardt were Derek Greenfield, Ann McEvoy, Hari Shroff, Gavin Crooks, Ned Wingreen and Eric Betzig.
Key to a cell's survival is the manner in which its critical components proteins, li
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DOE/Lawrence Berkeley National Laboratory