Open AccessAccurate measurement of fast endocytic recycling kinetics in real time
Author(s) -
Caspar T. H. Jonker,
Claire Deo,
Patrick J. Zager,
Aria. Tkachuk,
Alan M. Weinstein,
Enrique Rodríguez-Boulan,
Luke D. Lavis,
Ryan Schreiner
Publication year - 2019
Publication title -
journal of cell science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.384
H-Index - 278
eISSN - 1477-9137
pISSN - 0021-9533
DOI - 10.1242/jcs.231225
Subject(s) - endocytosis , endocytic cycle , endosome , transferrin receptor , biology , receptor , microbiology and biotechnology , kinetics , membrane , transferrin , cell , receptor mediated endocytosis , cell membrane , biophysics , biochemistry , physics , quantum mechanics
The fast turnover of membrane components through endocytosis and recycling allows precise control of the composition of the plasma membrane. Endocytic recycling can be rapid with some molecules returning to the plasma membrane with a t1/2<5 minutes. Existing methods to study these trafficking pathways utilize chemical, radioactive, or fluorescent labeling of cell surface receptors in pulse-chase experiments, which require tedious washing steps and manual collection of samples. Here, we introduce a live-cell endocytic recycling assay, based on a newly designed cell-impermeable, fluorogenic ligand for HaloTag: ‘Janelia Fluor 635i’ (JF635i; i=impermeant) which allows real-time detection of membrane receptor recycling at steady state. We used this method to study the effect of iron depletion on transferrin receptor (TfR) recycling using the chelator desferrioxamine. We found this perturbation significantly increases the TfR recycling rate. The high temporal resolution and simplicity of this assay provides a clear advantage over extant methods and makes it ideal for large scale cellular imaging studies. This assay can be adapted to examine other cellular kinetic parameters such as protein turnover and biosynthetic trafficking.