title: Asymmetric formation of coated pits on dorsal and ventral surfaces at the leading edges of motile cells and on protrusions of immobile cells.
abstract: Clathrin/AP2-coated vesicles are the principal endocytic carriers originating at the plasma membrane. In the experiments reported here, we used spinning-disk confocal and lattice light-sheet microscopy to study the assembly dynamics of coated pits on the dorsal and ventral membranes of migrating U373 glioblastoma cells stably expressing AP2 tagged with enhanced green fluorescence (AP2-EGFP) and on lateral protrusions from immobile SUM159 breast carcinoma cells, gene-edited to express AP2-EGFP. On U373 cells, coated pits initiated on the dorsal membrane at the front of the lamellipodium and at the approximate boundary between the lamellipodium and lamella and continued to grow as they were swept back toward the cell body; coated pits were absent from the corresponding ventral membrane. We observed a similar dorsal/ventral asymmetry on membrane protrusions from SUM159 cells. Stationary coated pits formed and budded on the remainder of the dorsal and ventral surfaces of both types of cells. These observations support a previously proposed model that invokes net membrane deposition at the leading edge due to an imbalance between the endocytic and exocytic membrane flow at the front of a migrating cell.
authors: Department of Cell Biology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115 Department of Physics, The Ohio State University, Columbus, OH 43210 kirchhausen@crystal.harvard.edu kural.1@osu.edu.
authors: Comert
authors: C
authors: Kural
authors: Biophysics Graduate Program, The Ohio State University, Columbus, OH 43210.
authors: Ahmet Ata
authors: AA
authors: Akatay
authors: Department of Cell Biology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115.
authors: Raphaël
authors: R
authors: Gaudin
authors: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147.
authors: Bi-Chang
authors: BC
authors: Chen
authors: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147.
authors: Wesley R
authors: WR
authors: Legant
authors: Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147.
authors: Eric
authors: E
authors: Betzig
authors: Department of Cell Biology, Harvard Medical School, and Program in Cellular and Molecular Medicine, Boston Children's Hospital, Boston, MA 02115 Department of Pediatrics, Harvard Medical School, Boston, MA 02115 kirchhausen@crystal.harvard.edu kural.1@osu.edu.
authors: Tom
authors: T
authors: Kirchhausen
mesh_terms: D033962:Adaptor Protein Complex 2 / Q000032:analysis; D001943:Breast Neoplasms / Q000503:physiopathology; D045744:Cell Line, Tumor; D002465:Cell Movement; D022081:Cell Surface Extensions / Q000502:physiology* / Q000648:ultrastructure; D003034:Coated Pits, Cell-Membrane / Q000648:ultrastructure*; D005260:Female; D005909:Glioblastoma / Q000503:physiopathology; D006801:Humans
chemical_list: D033962:Adaptor Protein Complex 2