Effect of Lipid Modification on Transformation - Associated Properties and Viral Membrane Assembly

181 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981.We have developed the methodology to systematically alter the phospholipid and fatty acid composition of the cellular membranes in chicken embryo fibroblasts. We have used this technique to study the effect of lipid modification on various parameters associated with transformation in tissue culture. Lipid supplementation had a variety of effects on cellular morphology, adhesion, cell surface proteins, and cell growth. These studies led to the observation that the standard lipid composition of the plasma membrane between normal and transformed cells was different. It was found that the transformed cells had a more rigid plasma membrane, as measured by DPH fluorescence polarization. The increased polarization was correlated with a higher phosphatidylethanolamine/phosphatidylcholine ratio in the transformed cell plasma membrane, as well as differences in the fatty acid composition.The lipid supplementation technique was further extended to study the assembly of Rous sarcoma virus and vesicular stomatitis virus envelopes. It was found that both viruses change their phospholipid composition in a very different manner than did the host cell plasma membrane. The viruses appeared to select for pre-existing phospholipids and acquired the newly synthesized analogues at a much reduced rate than the host plasma membrane. From these studies it was inferred that the viruses selected for phospholipid polar head groups from localized lipid regions within the plasma membrane. These regions do not reflect the average or bulk lipid composition but rather reflect specific lipids selected for by the budding process.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD