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 (C-20-C-24 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 C-20-C-24 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 (C-16 and C-18 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 C-20-C-24 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.