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Rapid Recycling of β 2 ‐Adrenergic Receptors is Dependent on the Actin Cytoskeleton and Myosin Vb
Author(s) -
Millman Ellen E.,
Zhang Haibin,
Zhang Haixia,
Godines Veronica,
Bean Andrew J.,
Knoll Brian J.,
Moore Robert H.
Publication year - 2008
Publication title -
traffic
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.677
H-Index - 130
eISSN - 1600-0854
pISSN - 1398-9219
DOI - 10.1111/j.1600-0854.2008.00813.x
Subject(s) - myosin , biology , microbiology and biotechnology , cytoskeleton , actin , receptor , actin cytoskeleton , adrenergic receptor , genetics , cell
For the β 2 ‐adrenergic receptor (β 2 AR), published evidence suggests that an intact actin cytoskeleton is required for the endocytosis of receptors and their proper sorting to the rapid recycling pathway. We have characterized the role of the actin cytoskeleton in the regulation of β 2 AR trafficking in human embryonic kidney 293 (HEK293) cells using two distinct actin filament disrupting compounds, cytochalasin D and latrunculin B (LB). In cells pretreated with either drug, β 2 AR internalization into transferrin‐positive vesicles was not altered but both agents significantly decreased the rate at which β 2 ARs recycled to the cell surface. In LB‐treated cells, nonrecycled β 2 ARs were localized to early embryonic antigen 1‐positive endosomes and also accumulated in the recycling endosome (RE), but only a small fraction of receptors localized to LAMP‐positive late endosomes and lysosomes. Treatment with LB also markedly enhanced the inhibitory effect of rab11 overexpression on receptor recycling. Dissociating receptors from actin by expression of the myosin Vb tail fragment resulted in missorting of β 2 ARs to the RE, while the expression of various CART fragments or the depletion of actinin‐4 had no detectable effect on β 2 AR sorting. These results indicate that the actin cytoskeleton is required for the efficient recycling of β 2 ARs, a process that likely is dependent on myosin Vb.