Effect of low temperatures on the transfer of phospholipids with various acyl-chain lengths to the plasma membrane of leek cells.

The intracellular transport of lipids with very-long-chain acyl moieties (C20-C24 fatty acid-containing lipids) to the plasma membrane of leek cells follows the vesicular ER-Golgi apparatus-plasma membrane pathway. Here we report on the effect of low temperatures on the vesicular transport of lipids and especially C20-C24 fatty acid-containing lipids to the plasma membrane of leek cells. These lipids, normally transported through the ER-Golgi apparatus-plasma membrane pathway at 24 degrees C, accumulated in the ER and the Golgi apparatus at 12 degrees C with a related deficit in the plasma membrane. As lipids with long chain acyl moieties (C16 and C18 fatty acid-containing lipids) were still transferred to the plasma membrane at 12 degrees C, the data demonstrate a specific effect of low temperatures on the vesicular transfer of C20-C24 fatty acid-containing lipids to the plasma membrane of leek cells. Therefore, evidence is provided for distinct pathways and/or mechanisms transferring lipids to the plasma membrane of leek cells which differ in their sensitivity to low temperatures.