Imaging actin and dynamin recruitment during invagination of single clathrin-coated pits.
As a final step in endocytosis, clathrin-coated pits must separate from the plasma membrane and move into the cytosol as a coated vesicle. Because these events involve minute movements that conventional light microscopy cannot resolve, they have not been observed directly and their dynamics remain unexplored. Here, we used evanescent field (EF) microscopy to observe single clathrin-coated pits or vesicles as they draw inwards from the plasma membrane and finally lose their coats. This inward movement occurred immediately after a brief burst of dynamin recruitment and was accompanied by transient actin assembly. Therefore, dynamin may provide the trigger and actin may provide the force for movement into the cytosol.
Vollum Institute L-474, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Rd., Portland, OR 97201, USA.
Christien J
CJ
Merrifield
Morris E
ME
Feldman
Lei
L
Wan
Wolfhard
W
Almers
D016475:3T3 Cells; D000199:Actins / Q000378:metabolism*; D000818:Animals; D002966:Clathrin / Q000378:metabolism*; D003034:Coated Pits, Cell-Membrane / Q000378:metabolism*; D003599:Cytoskeleton / Q000378:metabolism; D034281:Dynamins; D004705:Endocytosis / Q000502:physiology; D020558:GTP Phosphohydrolases / Q000378:metabolism*; D007700:Kinetics; D051379:Mice; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009068:Movement
D000199:Actins; D002966:Clathrin; D020558:GTP Phosphohydrolases; D034281:Dynamins