What is the Membrane Biology Grand Challenge?

The Membrane Biology Grand Challenge is a large systems biology project aimed at gaining fundamental insights into the carbon-sequestration and circadian biology of cyanobacteria. Researchers from five institutions in the U.S. and one in Shanghai are collaborating to answer fundamental questions about the biology of cyanobacteria. The three to five year project began in 2005.

Goals

1. To investigate global biological carbon sequestration processes in Synechocystis 6803 and Cyanothece 51142.
2. To answer the question: How do the structure and dynamics of key membrane proteins regulate energy transduction, photosynthesis, hydrogen production, and metal ion homeostasis, and how is this regulation affected by the environment?
3. To develop software tools useful for #1 and #2.

Ultimately, the hope is to be able to engineer oxygenic photosynthetic microbes with enhanced carbon sequestration abilities.

Model System

The model system being employed is Cyanothece sp ATCC 51142. This unicellular cyanobacterium is capable of both oxygenic photosynthesis and N₂ fixation; photosynthesis in the daytime and N₂ fixation at night. Membrane proteins are believed to play key roles in these processes, but their identities and specific modes of action are poorly understood. Membrane systems and membrane proteins in Synechocystis, a related organism, have been implicated in the maintenance of this circadian rhythm, but much is still unknown regarding material transport, proximity of membrane systems, and the relationship between membrane processes, gene regulation and protein translation.

We have grown Cyanothece in defined culture conditions and entrained it to a 12 hr light/12 hr darkness cycle with samples being collected every two hours. Using those samples, we have sequenced and annotated the Cyanothece 51142 genome, purified various membrane fractions from cyanobacterial cells, and determined the structure of several of its proteins. We have built a bioreactor in which the Cyanothece is cultured, developed software tools to aid in the analysis of data gathered, been able to visualize in detail the cell membrane using TEM imaging, and produced a number of publications. More...

Collaborators

Pacific Northwest National Laboratory, Washington University in St. Louis, Purdue University, Saint Louis University, The Donald Danforth Plant Science Center, and Shanghai Institute for Plant Physiology & Ecology. More...Tokyo University (??) How to identify Teruo Ogawa's affiliation?

Funding

The research was performed as part of an EMSL Scientific Grand Challenge project at the W. R. Wiley Environmental Molecular Sciences Laboratory, a national scientific user facility sponsored by the U.S. Department of Energy's Office of Biological and Environmental Research (BER) program and located at Pacific Northwest National Laboratory. PNNL is operated for the Department of Energy by Battelle.