Using fluorescent sphingolipid analogs to study intracellular lipid trafficking.

Sphingolipids (SLs), including glycosphingolipids, are found on the plasma membrane where they play important roles in a wide variety of cell functions, including cell-cell communication, cell growth and differentiation, host-pathogen interactions, and cell-signaling events. This unit illustrates the use of fluorescent SL analogs to identify the mechanisms underlying SL endocytosis and subsequent intracellular trafficking. Techniques used to study SL domain formation at the plasma membrane, endocytic mechanisms and intracellular transport steps are highlighted. The use of biochemical treatments and dominant-negative protein expression to block specific steps in lipid trafficking are also discussed.