Close association between clathrin and the hydrophobic domain of boundary membranes in brain endocytic vesicles.
Purified bovine brain clathrin binds readily, in a pH-dependent fashion, to protein-free phospholipid bilayers. The association is tight and leads to inter-bilayer fusion, however, photolabeling studies using the amphiphilic photoreactive glycolipid 12-(4-azido-2-nitrophenoxy)stearoyl[1-14C]glucosamine provide no evidence for direct insertion of clathrin into the central, hydrophobic domain of of these target membranes. In contrast, similar photolabeling studies of isolated, intact clathrin-coated vesicles show that, in these structures, clathrin is readily accessible to a probe which is known to reside preferentially within the hydrophobic domain of the membrane. The results are consistent with a natural requirement, by clathrin, for accessory proteins in order to effect membrane penetration.
D000818:Animals; D001386:Azides; D001921:Brain / Q000378:metabolism / Q000648:ultrastructure*; D002417:Cattle; D002966:Clathrin / Q000378:metabolism*; D003034:Coated Pits, Cell-Membrane / Q000648:ultrastructure*; D004705:Endocytosis; D011992:Endosomes / Q000648:ultrastructure*; D006017:Glycolipids / Q000378:metabolism; D008051:Lipid Bilayers; D008563:Membrane Lipids / Q000378:metabolism*; D008854:Microscopy, Electron; D010743:Phospholipids; D010777:Photochemistry
D001386:Azides; D002966:Clathrin; D006017:Glycolipids; D008051:Lipid Bilayers; D008563:Membrane Lipids; D010743:Phospholipids; C019266:12-(4-azido-2-nitrophenoxy)stearoylglucosamine