Cargo-mediated regulation of a rapid Rab4-dependent recycling pathway.

Imagen de Guillermo Yudowski
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TítuloCargo-mediated regulation of a rapid Rab4-dependent recycling pathway.
Publication TypeJournal Article
Year of Publication2009
AutoresYudowski, GA, Puthenveedu, MA, Henry, AG, von Zastrow, M
JournalMol Biol Cell
Volume20
Issue11
Pagination2774-84
Date Published2009 Jun
ISSN1939-4586
Palabras claveAdrenergic beta-2 Receptor Antagonists, Adrenergic beta-Agonists, Animals, Cell Line, Cells, Cultured, Cyclic AMP-Dependent Protein Kinases, Endocytosis, Exocytosis, Green Fluorescent Proteins, Humans, Hydrogen-Ion Concentration, Isoproterenol, Microscopy, Fluorescence, Mutation, Neurons, Protein Transport, rab4 GTP-Binding Proteins, Rats, Receptors, Adrenergic, beta-2, Receptors, Transferrin, Signal Transduction, Time Factors
Abstract

Membrane trafficking is well known to regulate receptor-mediated signaling processes, but less is known about whether signaling receptors conversely regulate the membrane trafficking machinery. We investigated this question by focusing on the beta-2 adrenergic receptor (B2AR), a G protein-coupled receptor whose cellular signaling activity is controlled by ligand-induced endocytosis followed by recycling. We used total internal reflection fluorescence microscopy (TIR-FM) and tagging with a pH-sensitive GFP variant to image discrete membrane trafficking events mediating B2AR endo- and exocytosis. Within several minutes after initiating rapid endocytosis of B2ARs by the adrenergic agonist isoproterenol, we observed bright "puffs" of locally increased surface fluorescence intensity representing discrete Rab4-dependent recycling events. These events reached a constant frequency in the continuous presence of isoproterenol, and agonist removal produced a rapid (observed within 1 min) and pronounced (approximately twofold) increase in recycling event frequency. This regulation required receptor signaling via the cAMP-dependent protein kinase (PKA) and a specific PKA consensus site located in the carboxyl-terminal cytoplasmic tail of the B2AR itself. B2AR-mediated regulation was not restricted to this membrane cargo, however, as transferrin receptors packaged in the same population of recycling vesicles were similarly affected. In contrast, net recycling measured over a longer time interval (10 to 30 min) was not detectably regulated by B2AR signaling. These results identify rapid regulation of a specific recycling pathway by a signaling receptor cargo.

DOI10.1091/mbc.E08-08-0892
Alternate JournalMol. Biol. Cell
PubMed ID19369423
PubMed Central IDPMC2688556
Grant ListK99-DA023444 / DA / NIDA NIH HHS / United States
K99-DA024698 / DA / NIDA NIH HHS / United States
R00 DA023444 / DA / NIDA NIH HHS / United States
R00 DA023444-03 / DA / NIDA NIH HHS / United States
R00 DA024698 / DA / NIDA NIH HHS / United States
R01-DA012864 / DA / NIDA NIH HHS / United States