Increasing cellular lipid production by increasing the activity of diacylglycerol acyltransferase and decreasing the activity of triacylglycerol lipase
Disclosed are methods and compositions for increasing the triacylglycerol content of a cell by up-regulating diacylglycerol acyltransferase and down-regulating triacylglycerol lipase. In some embodiments, a DGA1 protein is expressed and a native TGL3 gene is knocked out, thereby increasing the synthesis of triacylglycerol and decreasing its consumption, respectively.
1. A transformed oleaginous cell, comprising a first genetic modification, wherein said first genetic modification comprises at least one extra copy of a heterologous diacylglycerol acyltransferase gene from, Rhodosporidium toruloides ; and a second genetic modification, wherein said second genetic modification is a triacylglycerol lipase knockout mutation in the oleaginous cell, wherein said transformed oleaginous cell accumulates more lipid than a non-transformed cell of the same species.
2. The transformed oleaginous cell of claim 1 , wherein said triacylglycerol lipase is TGL3.
3. The transformed oleaginous cell of claim 1 , wherein said first genetic modification encodes at least one copy of a diacylglycerol acyltransferase gene native to the oleaginous cell or from a different species.
4. The transformed oleaginous cell of claim 3 , wherein said diacylglycerol acyltransferase gene is a type I diacylglycerol acyltransferase gene, type II diacylglycerol acyltransferase gene, or type III diacylglycerol acyltransferase gene.
5. The transformed oleaginous cell of claim 4 , wherein said diacylglycerol acyltransferase gene is a type I diacylglycerol acyltransferase gene from Yarrowia lipolytica.
6. The transformed oleaginous cell of claim 4 , wherein said diacylglycerol acyltransferase gene is a type III diacylglycerol acyltransferase gene from Ricinus communis or Arachis hypogaea.
7. The transformed oleaginous cell of claim 4 , wherein said at least one copy of a diacylglycerol acyltransferase gene is integrated into the genome of said cell.
8. The transformed oleaginous cell of claim 1 , wherein said cell is selected from the group consisting of algae, bacteria, molds, fungi, plants, and yeasts.
9. The transformed oleaginous cell of claim 8 , wherein said cell is selected from the group consisting of Arxula, Saccharomyces and Yarrowia.
10. The transformed oleaginous cell of claim 9 , wherein said cell is selected from the group consisting of Arxula adenintvorans, Saccharomyces cerevisiae , and Yarrowia lipolytica.
11. The transformed of oleaginous cell of claim 1 , wherein said diacylglycerol acyltransferase gene comprises SEQ ID NO:6.
12. The transformed oleaginous cell of claim 1 , wherein said diacylglycerol acyltransferase gene is a type II diacylglycerol acyltransferase.
13. The transformed oleaginous cell of claim 1 , wherein said diacylglycerol acyltransferase gene is a type I diacylglycerol acyltransferase.