The primary function of the glycerides is energy storage.
The R group of the phosphoryl ester is choline.
The researchers initially investigated the progression of the disease in a mouse model. For this purpose, they constitutively activated mTOR specifically in liver cells. "We already knew that mTOR is involved in tumor development as it centrally controls cell growth. However, in the case of HCC we did not know which downstream metabolic and signaling pathways are affected," says Guri. The researchers have now discovered that mTORC2 - mTOR forms two protein complexes termed mTORC1 and mTORC2 - promotes the new synthesis of fatty acids and certain lipids. Most people do not realize that our body contains more lipid species than genes. It is assumed that there are thousands of different types," says Guri. "Together with Howard Riezman's team, we have been able to analyze a broad spectrum of such lipids."
They also are structural componentsof cellular membranes.
In hepatocytes, mTORC2 stimulates in particular the production of two lipid species important for cell growth: sphingolipids and cardiolipins. The first are structural components of cell membranes, which have to be continuously supplied in rapidly proliferating cells. Cardiolipins are located in the cellular powerhouse, the mitochondria, and are involved in energy production. By enhancing cardiolipin synthesis, the energy-hungry tumor cells ensure their energy supply. "Cancer cells depend on the new synthesis of fatty acids and lipids; if you turn off the tap, you stop the development of tumors."
Plant Fatty Acid Synthesis - AOCS Lipid Library
About 40% of the bodies caloric intake is derived from lipids and almost all of these calories come from fats, the . The fatty acid composition in terms of saturation (oxidation forms) is not uniform but varies with the origin. Plant fats contain more polyunsaturated fatty acids and animal fats contain more saturated fatty acids as well as cholesterol. Polyunsaturated fats are essential for humans because animals are not able to synthesize those on their own. Most lipids, however, have metabolic functions contributing to membrane structures and signaling. (C20:4) is a fatty acid which plays a central role as precursor for prostaglandin synthesis. Phospholipids are synthesized from diacylgycerolphosphate, a negatively charged phospholipid precursor and signaling molecule itself, carrying various hydrophilic and/or charged headgroups that determine the surface charge and chemical properties of biological membrane surfaces.