Metabolic engineering of lipid metabolism by improving fatty acid binding and transport

Abstract

CHI like fatty acid binding proteins and genes, recombinant cells and organisms, methods of metabolic pathway engineering to improve lipid production in cells, Crystal structures of CHI like fatty acid binding proteins, methods of engineering CHI like fatty acid binding proteins and systems thereof are provided.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to and full benefit of U.S. Ser. No. 60 / 831,046 filed Jul. 13, 2006, METABOLIC ENGINEERING OF LIPID METABOLISM BY IMPROVING FATTY ACID BINDING AND TRANSPORT by Pojer et al., the full disclosure of which is incorporated herein by reference in its entirety.STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT[0002]The application was supported in part by National Science Foundation MCB-0236027. The government may have certain rights in the invention.FIELD OF THE INVENTION[0003]This invention is in the field of metabolic pathway engineering of lipids in plants and in the field of protein crystallography and design.BACKGROUND[0004]Currently, the majority of vegetable oil production (estimated at 87 million metric tons with approximate market value of 40 billion U.S. dollars) goes into human consumption, with as much as 25% of human caloric intake in developed countries be...

AI Technical Summary

Benefits of technology

[0008]The present invention provides the discovery that chalcone isomerase like fatty acid binding proteins are likely fatty acid transporters that facilitate transport of fatty acids from the thylakoid membrane to the outer plastid envelope. This discovery provides a target for engineering lipid metabolism, e.g., in plants. For example, lipid production is likely to be increased by overexpressing chalcone isomerase like fatty acid binding proteins in cells of the plants. In addition, the complete crystal structures of two of these proteins are provided. This crystal structure information makes it possible to engineer the proteins to modulate fatty acid binding and plastid transport, e.g., to increase transport activity.

[0011]Optionally, the gene is highly expressed, e.g., more highly expressed than a corresponding native chalcone isomerase like fatty acid binding protein gene of the cell. This high level of expression increases lipid content of the recombinant cell as compared to a corresponding cell that does not express the gene. That is, the protein may regulate transport of the fatty acid from an inner thylakoid membrane of the cell to an outer membrane of a plastid of the cell, and over expression of the protein may increase plastid transport.

[0014]In a related aspect, the invention includes a recombinant cell that expresses a heterologous regulator of a chalcone isomerase like fatty acid binding protein gene. Such regulators include transcription factors that regulate expression of the gene, anti-sense nucleic acids that inhibit transcription or translation of an mRNA encoded by the gene, siRNAs that inhibits translation of an mRNA encoded by the gene, and miRNAs that inhibit translation of an mRNA encoded by the gene. The regulator can increase or decrease production of a chalcone isomerase like fatty acid binding protein in the cell, thereby increasing or decreasing lipid content of the cell. All of the above features apply to this embodiment as well, e.g., with respect to cells, plants, fatty acids, etc.

[0015]In another related aspect, an expression vector that encodes a chalcone isomerase like fatty acid binding protein is provided. All of the above features apply to this embodiment as well, e.g., the vector can encode the genes noted above, and can include an expression cassette expressible in a plant such as any of those noted above. A cassette of the vector is desirably configured for overexpression of the chalcone isomerase like fatty acid binding protein in a target cell (e.g., in a plant), e.g., to increase lipid production in the cell.

Problems solved by technology

Indeed, the complexity in determining trait-genotype associations for the seemingly simple trait of oil production has been demonstrated.

Without knowledge of how this mechanism works, efforts to increase flux through fatty acid synthesis pathways by metabolic engineering have been hampered.

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