Actin assembly plays a variable, but not obligatory role in receptor-mediated endocytosis in mammalian cells.
Three cell-permeant compounds, cytochalasin D, latrunculin A and jasplakinolide, which perturb intracellular actin dynamics by distinct mechanisms, were used to probe the role of filamentous actin and actin assembly in clathrin-mediated endocytosis in mammalian cells. These compounds had variable effects on receptor-mediated endocytosis of transferrin that depended on both the cell line and the experimental protocol employed. Endocytosis in A431 cells assayed in suspension was inhibited by latrunculin A and jaspiakinolide, but resistant to cytochalasin D, whereas neither compound inhibited endocytosis in adherent A431 cells. In contrast, endocytosis in adherent CHO cells was more sensitive to disruption of the actin cytoskeleton than endocytosis in CHO cells grown or assayed in suspension. Endocytosis in other cell types, including nonadherent K562 human erythroleukemic cells or adherent Cos-7 cells was unaffected by disruption of the actin cytoskeleton. While it remains possible that actin filaments can play an accessory role in receptor-mediated endocytosis, these discordant results indicate that actin assembly does not play an obligatory role in endocytic coated vesicle formation in cultured mammalian cells.
Fujimoto
L M
LM
Department of Cell Biology, Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA.
Roth
R
R
Heuser
J E
JE
Schmid
S L
SL
D000199:Actins / Q000737:chemistry / Q000502:physiology*; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000494:pharmacology; D016466:CHO Cells; D019556:COS Cells; D002460:Cell Line; D002462:Cell Membrane / Q000648:ultrastructure; D003034:Coated Pits, Cell-Membrane / Q000737:chemistry / Q000648:ultrastructure; D006224:Cricetinae; D015638:Cytochalasin D / Q000494:pharmacology; D003599:Cytoskeleton / Q000187:drug effects; D047630:Depsipeptides; D004705:Endocytosis; D005613:Freeze Etching; D006801:Humans; D020014:K562 Cells; D008856:Microscopy, Fluorescence; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D010456:Peptides, Cyclic / Q000494:pharmacology; D013844:Thiazoles / Q000494:pharmacology; D053778:Thiazolidines; D013997:Time Factors; D014168:Transferrin / Q000737:chemistry; D014407:Tumor Cells, Cultured
D000199:Actins; D000970:Antineoplastic Agents; D019086:Bridged Bicyclo Compounds, Heterocyclic; D047630:Depsipeptides; D019384:Nucleic Acid Synthesis Inhibitors; D010456:Peptides, Cyclic; D013844:Thiazoles; D053778:Thiazolidines; D014168:Transferrin; C057531:jasplakinolide; D015638:Cytochalasin D; C037067:latrunculin A