Lockshon, Daniel and Kerr, Emily O. and Learmonth, Robert P. and Kennedy, Brian K. (2007) The sensitivity of saccharomyces mutants to palmitoleic acid may provide a means to study the controls of membrane fluidity in eukaryotes. In: ICYGMB 2007: 23rd International Conference on Yeast Genetics and Molecular Biology, 1-6 Jul 2007, Melbourne, Australia.
The mechanisms which control the fluidity of eukaryotic membranes are unknown. We have identified S. cerevisiae deletion strains whose growth is impaired by palmitoleic (PO; C16:1) but not oleic (C18:1) acid. PO-sensitivity is suppressed by oleate thus perhaps identifying a signaling pathway that controls the ratio of these fatty acids in membrane phospholipid. Growth of these mutants is also inhibited by a known fluidizer, benzyl alcohol, thus indicating that PO has a fluidizing effect. Removal of Pkc1, known to play a key role in cell wall integrity control, leads to acute PO-sensitivity. Removal of Bck1, Mkk1, Mkk2, Slt2, or Swi6 downstream components of the cell wall integrity pathway, cause modest POsensitivity. Suppression by 1M sorbitol of the PO-sensitivity of these four mutants implies that PO/oleate ratio influences the cell wall. Acute PO-sensitivity of the pkc1Δ strain, even in the presence of 1M sorbitol, suggests the cell wall to be more severely compromised by PO addition to this strain. Alternatively, the failure to control the PO/oleate ratio could have an additional effect on the pkc1 strain, perhaps by disabling a 2nd pathway downstream of Pkc1 thus allowing PO addition to cause excess membrane fluidity. We are attempting to distinguish these two models by a variety of genetic, biochemical, and physical methods. Most notably, the effect of PO on the fluidity of the plasma membrane is being examined by measuring the depolarization of laurdan fluorescence.
|Item Type:||Conference or Workshop Item (Commonwealth Reporting Category E) (Paper)|
|Additional Information:||Abstract only. Awaiting full paper from authors.|
|Uncontrolled Keywords:||eukaryotic membranes; palmitoleic acid|
|Subjects:||270000 Biological Sciences > 270300 Microbiology > 270306 Microbial Genetics
270000 Biological Sciences > 270100 Biochemistry and Cell Biology > 270103 Protein Targeting and Signal Transduction
270000 Biological Sciences > 270100 Biochemistry and Cell Biology > 270104 Membrane Biology
|Depositing User:||Ms Debbie White|
|Date Deposited:||11 Oct 2007 01:19|
|Last Modified:||02 Jul 2013 22:48|
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