A review of one approach to bottom up assembly of minimal life

When seeking to assemble minimal life from the bottom up in wet carbon chemistry, the critical properties of life apparently emerge from the interconnected functions of three subsystems: information, metabolism and container. Such interconnected supramolecular systems, so-called protocells, are under the right circumstances able to mimic the main functions of a living cell although in a very simplified manner. Seeking to create minimal life from the top down leads us to a somewhat different picture, where construction of synthetic / streamlined genomes become the critical scientific issue. How to integrate the knowledge we obtain from the top downand the bottom up approaches is a great challenge for our and related communities and a good problem to discuss at this meeting. In technical terms, our bottom up team explores ruthenium-based photocatalysis as metabolism, fatty acids vesicles, oil droplets and reverse micelles as containers and lipophilic XNA as minimal informational systems. Based on our experimental, computational and theoretical work we review protocell feeding, growth, division, motility, and information controlled metabolic production of containers. Finally, we demonstrate preliminary integration of biochemicaland microelectromechanical (MEMS) systems where life-like information processing and material production occur and interact in different medi and as such form an exciting frontier for the study of artificial life. 1 Rasmussen S, et al., Protocells: Bridging nonliving & living matter, MIT Press, 2009 2 Gibson DG, et al (2010) Creation of a bacterial cell controlled by a chemically synthesized genome. Science doi: 10.1126/science.1190719 3 Rasmussen S, Life after the synthetic cell – Bottom up will be telling more (2010), Nature, 465422a, May 20 4 Sunami T, et al., (2010) Detection of association and fusion of giant vesicles using a fluorescence-activated cell sorter, Langmuir 26: 15098 5 Porcar M, et al., (2011), Ten grand challenges for synthetic life, to appear in Synthetic Biology. 6 Rasmussen S, et al., (2003) Bridging nonliving and living matter, Artificial Life 9; 269 7 Rasmussen S, et al.,(2004) Transitions from nonliving to living matter, Science 303: 963 8 Fellermann H, et al., (2007) Life-cycle of a minimal protocell – A dissipative particle dynamics study, Artificial Life 13; 319 9 DeClue M, et al., (2009) Nucleobase mediated, photocatalytic vesicle formation from ester precursor molecules, JACS 131 931 10 Toyota T, et al., (2009) Self-propelled oil droplets consuming “fuel” surfactant. JACS 11 Maurer S, et al., (2011) Interactions between catalysts and amphiphilic structures and the implications for a protocell model. Chem Phys Chem 12; 828 12 http://www.fp7-matchit.eu 13 McCaskill, p. 253, in Protocells: Bridging nonliving & living matter, eds Rasmussen S, et al., MIT Press, 2009