Fig. 1.

Cartoon illustrating the sequential steps involved in the uptake of long-chain fatty acids by cells. 1. Release of fatty acids from (interstitial) albumin. 2. Binding in the hydrophobic cavity of CD36 which can accommodate up to two fatty acids at a time. 3. Guidance of the fatty acid through the CD36 ectodomain interior to pass the unstirred water layer and be exposed to the plasma membrane surface. 4. Exit of the fatty acid from CD36 to the outer leaflet of the phospholipid bilayer. 5. Transmembrane translocation (‘flip-flop’) of single fatty acids. 6. Desorption of fatty acids from the inner leaflet of the phospholipid bilayer and binding to the interior of FABP that is anchored by binding to the intracellular part of CD36. 7. Diffusion into the soluble cytoplasm of the fatty acid-FABP complex toward sites of intracellular fatty acid metabolism. Note that proteins and membranes and their putative mutual interactions are not drawn to scale.